@article{kim_ye_lee_lu_2024, title={A Contextually Supervised Optimization-Based HVAC Load Disaggregation Methodology}, volume={15}, ISSN={["1949-3061"]}, url={https://doi.org/10.1109/TSG.2024.3367301}, DOI={10.1109/TSG.2024.3367301}, number={4}, journal={IEEE TRANSACTIONS ON SMART GRID}, author={Kim, Hyeonjin and Ye, Kai and Lee, Duehee and Lu, Ning}, year={2024}, month={Jul}, pages={3852–3863} } @article{lee_rehm_makdad_miller_lu_2024, title={A Novel Power-Band Based Data Segmentation Method for Enhancing Meter Phase and Transformer-Meter Pairing Identification}, url={https://doi.org/10.1109/TPWRD.2024.3402263}, DOI={10.1109/TPWRD.2024.3402263}, abstractNote={This paper presents a novel power-band-based data segmentation (PBDS) method to enhance the identification of meter phase and meter-transformer pairing. Meters that share the same transformer or are on the same phase typically exhibit strongly correlated voltage profiles. However, under high power consumption, there can be significant voltage drops along the line connecting a customer to the distribution transformer. These voltage drops significantly decrease the correlations among meters on the same phase or supplied by the same transformer, resulting in high misidentification rates. To address this issue, we propose using power bands to select highly correlated voltage segments for computing correlations, rather than relying solely on correlations computed from the entire voltage waveforms. The algorithm's performance is assessed by conducting tests using data gathered from 13 utility feeders. To ensure the credibility of the identification results, utility engineers conduct field verification for all 13 feeders. The verification results unequivocally demonstrate that the proposed algorithm surpasses existing methods in both accuracy and robustness.}, journal={IEEE Transactions on Power Delivery}, author={Lee, Han Pyo and Rehm, PJ and Makdad, Matthew and Miller, Edmond and Lu, Ning}, year={2024} } @article{hu_shirsat_muthukaruppan_li_zhang_tang_baran_lu_2024, title={Adaptive cold-load pickup considerations in 2-stage microgrid unit commitment for enhancing microgrid resilience}, volume={356}, ISSN={["1872-9118"]}, DOI={10.1016/j.apenergy.2023.122424}, abstractNote={In an extended main grid outage spanning multiple days, load shedding serves as a critical mechanism for islanded microgrids to maintain essential power and energy reserves that are indispensable for fulfilling reliability and resiliency mandates. However, using load shedding for such purposes leads to increasing occurrence of cold load pickup (CLPU) events. This study presents an innovative adaptive CLPU model that introduces a method for determining and incorporating parameters related to CLPU power and energy requirements into a two-stage microgrid unit commitment (MGUC) algorithm. In contrast to the traditional fixed-CLPU-curve approach, this model calculates CLPU duration, power, and energy demands by considering outage durations and ambient temperature variations within the MGUC process. By integrating the adaptive CLPU model into the MGUC problem formulation, it allows for the optimal allocation of energy resources throughout the entire scheduling horizon to fulfill the CLPU requirements when scheduling multiple CLPU events. The performance of the enhanced MGUC algorithm considering CLPU needs is assessed using actual load and photovoltaic (PV) data. Simulation results demonstrate significant improvements in dispatch optimality evaluated by the amount of load served, customer comfort, energy storage operation, and adherence to energy schedules. These enhancements collectively contribute to reliable and resilient microgrid operation.}, journal={APPLIED ENERGY}, author={Hu, Rongxing and Shirsat, Ashwin and Muthukaruppan, Valliappan and Li, Yiyan and Zhang, Si and Tang, Wenyuan and Baran, Mesut and Lu, Ning}, year={2024}, month={Feb} } @article{lee_li_song_wu_lu_2024, title={An iterative bidirectional gradient boosting approach for CVR baseline estimation}, volume={369}, ISSN={["1872-9118"]}, url={https://doi.org/10.1016/j.apenergy.2024.123456}, DOI={10.1016/j.apenergy.2024.123456}, abstractNote={This paper presents a novel Iterative Bidirectional Gradient Boosting Model (IBi-GBM) for estimating the baseline of Conservation Voltage Reduction (CVR) programs. In contrast to many existing methods, we treat CVR baseline estimation as a missing data retrieval problem. The approach involves dividing the load and its corresponding temperature profiles into three periods: pre-CVR, CVR, and post-CVR. To restore the missing load profile during the CVR period, the method employs a three-step process. First, a forward-pass GBM is executed using data from the pre-CVR period as inputs. Subsequently, a backward-pass GBM is applied using data from the post-CVR period. The two restored load profiles are reconciled, considering pre-calculated weights derived from forecasting accuracy, and only the leftmost and rightmost points are retained. The newly restored points are then included as inputs for the subsequent iteration. This iterative procedure continues until the original load data in the CVR period is fully restored. We develop IBi-GBM using actual smart meter and Supervisory Control and Data Acquisition (SCADA) data. Our results demonstrate that IBi-GBM exhibits robust performance across various data resolutions and in different seasons and outperforms existing methods by achieving a 1%–2% reduction in normalized Root Mean Square Error (nRMSE).}, journal={APPLIED ENERGY}, author={Lee, Han Pyo and Li, Yiyan and Song, Lidong and Wu, Di and Lu, Ning}, year={2024}, month={Sep} } @article{hu_ye_kim_lu_2024, title={BERT-PIN: A BERT-Based Framework for Recovering Missing Data Segments in Time-Series Load Profiles}, volume={7}, ISSN={["1941-0050"]}, url={https://doi.org/10.1109/TII.2024.3417272}, DOI={10.1109/TII.2024.3417272}, journal={IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS}, author={Hu, Yi and Ye, Kai and Kim, Hyeonjin and Lu, Ning}, year={2024}, month={Jul} } @article{wu_guerrero_wu_bazmohammadi_vasquez_cabrera_lu_2024, title={Digital Twins for Microgrids: Opening a New Dimension in the Power System}, volume={22}, ISSN={["1558-4216"]}, url={https://doi.org/10.1109/MPE.2023.3324296}, DOI={10.1109/MPE.2023.3324296}, abstractNote={The need for affordable, reliable, sustainable, and modern energy is now more important than ever because of the climate crisis. Climate change will push up to 130 million people into poverty over the next 10 years and continue to cause more unpredictable natural disasters, such as cyclones, flooding, earthquakes, landslides, tsunamis, and volcanic eruptions. Power outages do not occur only in remote rural areas but also in developed countries, lasting for several hours and even a couple of days, due to the extreme weather in recent years. Microgrids, as a flexible architecture capable of integrating local distributed energy resources (DERs), can satisfy wide-ranging demands via their variable solutions, from off-grid to on-grid applications.}, number={1}, journal={IEEE POWER & ENERGY MAGAZINE}, author={Wu, Ying and Guerrero, Josep M. and Wu, Yanpeng and Bazmohammadi, Najmeh and Vasquez, Juan C. and Cabrera, Andrea Justo and Lu, Ning}, year={2024}, month={Jan}, pages={35–42} } @article{li_song_hu_lee_wu_rehm_lu_2024, title={Load Profile Inpainting for Missing Load Data Restoration and Baseline Estimation}, volume={15}, ISSN={["1949-3061"]}, url={https://doi.org/10.1109/TSG.2023.3293188}, DOI={10.1109/TSG.2023.3293188}, abstractNote={This paper introduces a Generative Adversarial Nets (GAN) based, Load Profile Inpainting Network (Load-PIN) for restoring missing load data segments and estimating the baseline for a demand response event. The inputs are time series load data before and after the inpainting period together with explanatory variables (e.g., weather data). We propose a Generator structure consisting of a coarse network and a fine-tuning network. The coarse network provides an initial estimation of the data segment in the inpainting period. The fine-tuning network consists of self-attention blocks and gated convolution layers for adjusting the initial estimations. Loss functions are specially designed for the fine-tuning and the discriminator networks to enhance both the point-to-point accuracy and realisticness of the results. We test the Load-PIN on three real-world data sets for two applications: patching missing data and deriving baselines of conservation voltage reduction (CVR) events. We benchmark the performance of Load-PIN with five existing deep-learning methods. Our simulation results show that, compared with the state-of-the-art methods, Load-PIN can handle varying-length missing data events and achieve 15%-30% accuracy improvement.}, number={2}, journal={IEEE TRANSACTIONS ON SMART GRID}, author={Li, Yiyan and Song, Lidong and Hu, Yi and Lee, Hanpyo and Wu, Di and Rehm, P. J. and Lu, Ning}, year={2024}, month={Mar}, pages={2251–2260} } @article{hu_li_song_lee_rehm_makdad_miller_lu_2024, title={MultiLoad-GAN: A GAN-Based Synthetic Load Group Generation Method Considering Spatial-Temporal Correlations}, volume={15}, ISSN={["1949-3061"]}, url={https://doi.org/10.1109/TSG.2023.3302192}, DOI={10.1109/TSG.2023.3302192}, abstractNote={This paper presents a deep-learning framework, Multi-load Generative Adversarial Network (MultiLoad-GAN), for generating a group of synthetic load profiles (SLPs) simultaneously. The main contribution of MultiLoad-GAN is the capture of spatial-temporal correlations among a group of loads that are served by the same distribution transformer. This enables the generation of a large amount of correlated SLPs required for microgrid and distribution system studies. The novelty and uniqueness of the MultiLoad-GAN framework are three-fold. First, to the best of our knowledge, this is the first method for generating a group of load profiles bearing realistic spatial-temporal correlations simultaneously. Second, two complementary realisticness metrics for evaluating generated load profiles are developed: computing statistics based on domain knowledge and comparing high-level features via a deep-learning classifier. Third, to tackle data scarcity, a novel iterative data augmentation mechanism is developed to generate training samples for enhancing the training of both the classifier and the MultiLoad-GAN model. Simulation results show that MultiLoad-GAN can generate more realistic load profiles than existing approaches, especially in group level characteristics. With little finetuning, MultiLoad-GAN can be readily extended to generate a group of load or PV profiles for a feeder or a service area.}, number={2}, journal={IEEE TRANSACTIONS ON SMART GRID}, author={Hu, Yi and Li, Yiyan and Song, Lidong and Lee, Han Pyo and Rehm, P. J. and Makdad, Matthew and Miller, Edmond and Lu, Ning}, year={2024}, month={Mar}, pages={2309–2320} } @book{lu_2024, title={Photovoltaic Analysis and Response Support (PARS) Platform for Solar Situational Awareness and Resiliency Services}, url={https://doi.org/10.2172/2349508}, DOI={10.2172/2349508}, abstractNote={The project's primary objective is to develop a digital-twin based Photovoltaic (PV) Analysis and Response Support (PARS) platform, which aims to provide real-time situational awareness and optimal response plans. This platform is designed to enhance the performance of hybrid PV systems, making them competitive with or even superior to conventional generation resources. The PARS platform enabled the project team to develop and evaluate an extensive suite of grid support functionalities for the hybrid PV systems to enhance grid performance, across key areas including visibility, dispatchability, security, resilience, and reliability. Given the global push toward achieving 100% clean energy by 2035, there is a significant increase in the integration of inverter-based resources (IBRs) throughout the energy grid. Effectively managing the inherent variability and uncertainty associated with IBRs is crucial for ensuring cost-effectiveness, reliability, and security in both the main grid and islanded microgrids. Constrained to a limited array of IEEE test systems or standard feeder models, traditional IBR modeling struggles to assimilate new field data, accurately reflect system dynamics, and adapt to the evolving energy landscape. In our project, we embraced a Digital Twin (DT) strategy for crafting the PARS platform. A digital twin acts as a precise virtual counterpart of a physical system, built on historical data and continuously honed with real-time insights. This enables the high-fidelity DT to accurately mirror current system operations and forecast future scenarios. Consequently, the PARS platform becomes an ideal environment for testing and refining monitoring, control, power, and energy management algorithms designed to boost hybrid PV system performance. The defining feature of the PARS platform, distinguishing it from other advanced simulation tools, is its exceptional adaptability. This is achieved by employing actual network topologies and utilizing real-time field data for fine-tuning and calibration, ensuring a close emulation of real-world conditions. The project deliverables include: 1) High-fidelity IBR models and tools for real-time parameterization, utilizing real-time field measurements to refine IBR models for enhanced accuracy and performance; 2) Grid-forming and Grid-following capabilities to deliver resilience services, including blackstart, voltage and frequency support, cold-load pick-up, power reserves, and three-phase load balancing across grid-connected and microgrid settings; 3) Machine learning-based forecasting tools and methods for generating synthetic data and topologies, creating diverse and realistic simulation environments for evaluating varied operational scenarios; 4) Advanced microgrid power and energy management algorithms for optimizing the integration and operation of PV, storage, and demand response resources within both feeder and community scales. The power grid data sets are provided by four utility companies in North Carolina and the New York Power Administration. Acting as industry advisors, our industry partners communicated stakeholder needs and regulatory standards to the research teams, aiding technology transfer by incorporating the developed methodologies into their daily operations. This collaboration ensures that the PARS platform, functioning as a power system digital twin, enhances our understanding of IBR dynamic behaviors and enables the development and evaluation of IBR control functions that match or exceed the capabilities of conventional synchronous generators.}, author={Lu, Ning}, year={2024}, month={Mar} } @article{xu_paduani_xiao_song_lubkeman_lu_2024, title={Under-Frequency Load Shedding for Power Reserve Management in Islanded Microgrids}, url={https://doi.org/10.1109/TSG.2024.3393426}, DOI={10.1109/TSG.2024.3393426}, journal={IEEE Transactions on Smart Grid}, author={Xu, Bei and Paduani, Victor and Xiao, Qi and Song, Lidong and Lubkeman, David and Lu, Ning}, year={2024} } @article{ye_kim_hu_lu_wu_rehm_2023, title={A Modified Sequence-to-point HVAC Load Disaggregation Algorithm}, ISSN={["1944-9925"]}, DOI={10.1109/PESGM52003.2023.10252553}, abstractNote={This paper presents a modified sequence-to-point (S2P) algorithm for disaggregating the heat, ventilation, and air conditioning (HVAC) load from the total building electricity consumption. The original S2P model is convolutional neural network (CNN) based, which uses load profiles as inputs. We propose three modifications. First, the input convolution layer is changed from 1D to 2D so that normalized temperature profiles are also used as inputs to the S2P model. Second, a drop-out layer is added to improve adaptability and generalizability so that the model trained in one area can be transferred to other geographical areas without labelled HVAC data. Third, a fine-tuning process is proposed for areas with a small amount of labelled HVAC data so that the pre-trained S2P model can be fine-tuned to achieve higher disaggregation accuracy (i.e., better transferability) in other areas. The model is first trained and tested using smart meter and sub-metered HVAC data collected in Austin, Texas. Then, the trained model is tested on two other areas: Boulder, Colorado and San Diego, California. Simulation results show that the proposed modified S2P algorithm outperforms the original S2P model and the support-vector machine based approach in accuracy, adaptability, and transferability.}, journal={2023 IEEE POWER & ENERGY SOCIETY GENERAL MEETING, PESGM}, author={Ye, Kai and Kim, Hyeonjin and Hu, Yi and Lu, Ning and Wu, Di and Rehm, P. J.}, year={2023} } @article{shirsat_muthukaruppan_hu_paduani_xu_song_li_lu_baran_lubkeman_et al._2023, title={A Secure and Adaptive Hierarchical Multi-Timescale Framework for Resilient Load Restoration Using a Community Microgrid}, volume={14}, ISSN={["1949-3037"]}, url={https://doi.org/10.1109/TSTE.2023.3251099}, DOI={10.1109/TSTE.2023.3251099}, abstractNote={Distribution system integrated community microgrids (CMGs) can partake in restoring loads during extended duration outages. At such times, the CMGs are challenged with limited resource availability, absence of robust grid support, and heightened demand-supply uncertainty. This paper proposes a secure and adaptive three-stage hierarchical multi-timescale framework for scheduling and real-time (RT) dispatch of CMGs with hybrid PV systems to address these challenges. The framework enables the CMG to dynamically expand its boundary to support the neighboring grid sections and is adaptive to the changing forecast error impacts. The first stage solves a stochastic extended duration scheduling (EDS) problem to obtain referral plans for optimal resource rationing. The intermediate near-real-time (NRT) scheduling stage updates the EDS schedule closer to the dispatch time using new obtained forecasts, followed by the RT dispatch stage. To make the decisions more secure and robust against forecast errors, a novel concept called delayed recourse is designed. The approach is evaluated via numerical simulations on a modified IEEE 123-bus system and validated using OpenDSS and hardware-in-loop simulations. The results show superior performance in maximizing load supply and continuous secure distribution network operation under different operating scenarios.}, number={2}, journal={IEEE TRANSACTIONS ON SUSTAINABLE ENERGY}, author={Shirsat, Ashwin and Muthukaruppan, Valliappan and Hu, Rongxing and Paduani, Victor Daldegan and Xu, Bei and Song, Lidong and Li, Yiyan and Lu, Ning and Baran, Mesut and Lubkeman, David and et al.}, year={2023}, month={Apr}, pages={1057–1075} } @article{li_song_zhang_kraus_adcox_willardson_komandur_lu_2023, title={A TCN-Based Hybrid Forecasting Framework for Hours-Ahead Utility-Scale PV Forecasting}, url={https://doi.org/10.1109/TSG.2023.3236992}, DOI={10.1109/TSG.2023.3236992}, abstractNote={This paper presents a Temporal Convolutional Network (TCN) based hybrid PV forecasting framework for enhancing hours-ahead utility-scale PV forecasting. The hybrid framework consists of two forecasting models: a physics-based trend forecasting (TF) model and a data-driven fluctuation forecasting (FF) model. Three TCNs are integrated in the framework for: i) blending the inputs from different Numerical Weather Prediction sources for the TF model to achieve superior performance on forecasting hourly PV profiles, ii) capturing spatial-temporal correlations between detector sites and the target site in the FF model to achieve more accurate forecast of intra-hour PV power drops, and iii) reconciling TF and FF results to obtain coherent hours-ahead PV forecast with both hourly trends and intra-hour fluctuations well preserved. To automatically identify the most contributive neighboring sites for forming a detector network, a scenario-based correlation analysis method is developed, which significantly improves the capability of the FF model on capturing large power fluctuations caused by cloud movements. The framework is developed, tested, and validated using actual PV data collected from 95 PV farms in North Carolina. Simulation results show that the performance of 6 hours ahead PV power forecasting is improved by 20% - 30% compared with state-of-the-art methods.}, journal={IEEE Transactions on Smart Grid}, author={Li, Yiyan and Song, Lidong and Zhang, Si and Kraus, Laura and Adcox, Taylor and Willardson, Roger and Komandur, Abhishek and Lu, Ning}, year={2023}, month={Sep} } @article{lee_dsouza_chen_lu_baran_2023, title={Adopting Dynamic VAR Compensators to Mitigate PV Impacts on Unbalanced Distribution Systems}, volume={11}, ISSN={["2169-3536"]}, url={https://doi.org/10.1109/ACCESS.2023.3315601}, DOI={10.1109/ACCESS.2023.3315601}, abstractNote={The growing integration of distributed energy resources into distribution systems poses challenges for voltage regulation. Dynamic VAR Compensators (DVCs) are a new generation of power electronics-based Volt/VAR compensation devices designed to address voltage issues in distribution systems with a high penetration of renewable generation resources. Currently, the IEEE Std. 1547-based Volt/VAR Curve (VV-C) is widely used as the local control scheme for controlling a DVC. However, the effectiveness of this scheme is not well documented, and there is limited literature on alternative control and placement schemes that can maximize the effective use of a DVC. In this paper, we propose an optimal dispatch and control mechanism to enhance the conventional VV-C based localized DVC control. First, we establish a multi-objective optimization framework to identify the optimal dispatch strategy and suitable placement for the DVC. Next, we introduce two supervisory control strategies to determine the appropriate instances for adjusting the VV-C when the operating condition changes. The outlined scheme comprises two primary stages: time segmentation and VV-C fitting. Within this framework, each time segment aims to produce optimized Q-V trajectories. The proposed method is tested on a modified IEEE 123-bus test system using OpenDSS for a wide range of operating scenarios, including sunny and cloudy days. Simulation results demonstrate that the proposed scheme effectively reduces voltage variations compared to the standard VV-C specified in IEEE Std. 1547.}, journal={IEEE ACCESS}, author={Lee, Han Pyo and Dsouza, Keith and Chen, Ke and Lu, Ning and Baran, Mesut E.}, year={2023}, pages={101514–101524} } @article{kim_ye_lee_hu_lu_wu_rehm_2023, title={An ICA-Based HVAC Load Disaggregation Method Using Smart Meter Data}, ISSN={["2167-9665"]}, DOI={10.1109/ISGT51731.2023.10066402}, abstractNote={This paper presents an independent component analysis (ICA) based unsupervised-learning method for heat, ventilation, and air-conditioning (HVAC) load disaggregation using low-resolution (e.g., 15 minutes) smart meter data. We first demonstrate that electricity consumption profiles on mild-temperature days can be used to estimate the non-HVAC base load on hot days. A residual load profile can then be calculated by subtracting the mild-day load profile from the hot-day load profile. The residual load profiles are processed using ICA for HVAC load extraction. An optimization-based algorithm is proposed for post-adjustment of the ICA results, considering two bounding factors for enhancing the robustness of the ICA algorithm. First, we use the hourly HVAC energy bounds computed based on the relationship between HVAC load and temperature to remove unrealistic HVAC load spikes. Second, we exploit the dependency between the daily nocturnal and diurnal loads extracted from historical meter data to smooth the base load profile. Pecan Street data with sub-metered HVAC data were used to test and validate the proposed methods. Simulation results demonstrated that the proposed method is computationally efficient and robust across multiple customers.}, journal={2023 IEEE POWER & ENERGY SOCIETY INNOVATIVE SMART GRID TECHNOLOGIES CONFERENCE, ISGT}, author={Kim, Hyeonjin and Ye, Kai and Lee, Han Pyo and Hu, Rongxing and Lu, Ning and Wu, Di and Rehm, P. J.}, year={2023} } @article{lee_song_li_lu_wu_rehm_makdad_miller_2023, title={An Iterative Bidirectional Gradient Boosting Algorithm for CVR Baseline Estimation}, ISSN={["1944-9925"]}, DOI={10.1109/PESGM52003.2023.10252215}, abstractNote={This paper presents a novel iterative, bidirectional, gradient boosting (bidirectional-GB) algorithm for estimating the baseline of the Conservation Voltage Reduction (CVR) program. We define the CVR baseline as the load profile during the CVR period if the substation voltage is not lowered. The proposed algorithm consists of two key steps: selection of similar days and iterative bidirectional-GB training. In the first step, preand post-event temperature profiles of the targeted CVR day are used to select similar days from historical non-CVR days. In the second step, the pre-event and post-event similar days are used to train two GBMs iteratively: a forward-GBM and a backwardGBM. After each iteration, the two generated CVR baselines are reconciled and only the first and the last points on the reconciled baseline are kept. The iteration repeats until all CVR baseline points are generated. We tested two gradient boosting methods (i.e., GBM and LighGBM) with two data resolutions (i.e., 15and 30-minute). The results demonstrate that both the accuracy and performance of the algorithm are satisfactory.}, journal={2023 IEEE POWER & ENERGY SOCIETY GENERAL MEETING, PESGM}, author={Lee, Han Pyo and Song, Lidong and Li, Yiyan and Lu, Ning and Wu, Di and Rehm, P. J. and Makdad, Matthew and Miller, Edmond}, year={2023} } @article{hu_ye_kim_lee_lu_wu_rehm_2023, title={Design Considerations of a Coordinative Demand Charge Mitigation Strategy}, ISSN={["1944-9925"]}, DOI={10.1109/PESGM52003.2023.10252618}, abstractNote={This paper presents a coordinative demand charge mitigation (DCM) strategy for reducing electricity consumption during system peak periods. Available DCM resources include batteries, diesel generators, controllable appliance loads, and conservation voltage reduction. All resources are directly controlled by load serving entities. A mixed integer linear programming-based energy management algorithm is developed to optimally coordinate DCM resources considering the load payback effect. To better capture system peak periods, two different kinds of load forecast are used: the day-ahead load forecast and the peak-hour probability forecast. Five DCM strategies are compared for reconciling the discrepancy between the two forecasting results. The DCM strategies are tested using actual utility data. Simulation results show that the proposed algorithm can effectively mitigate the demand charge while preventing the system peak from being shifted to the payback hours. We also identify the diminishing return effect, which can help load serving entities optimize the size of their DCM resources.}, journal={2023 IEEE POWER & ENERGY SOCIETY GENERAL MEETING, PESGM}, author={Hu, Rongxing and Ye, Kai and Kim, Hyeonjin and Lee, Hanpyo and Lu, Ning and Wu, Di and Rehm, P. J.}, year={2023} } @article{kamwa_liu_2023, title={How to keep the lights on: Lessons from major blackouts over the last 35 years [Editors’ voice]}, url={https://doi.org/10.1109/MPE.2023.3247106}, DOI={10.1109/MPE.2023.3247106}, abstractNote={At the time of this writing, in January 2023, Québec is remembering the 1998 ice storm, which occurred on Friday, 9 January, 34 years ago. Falls of more than 100 mm of freezing rain literally pulverized part of the Hydro-Québec electrical network, blacking out more than 4 million people. This day has gone down in history as Black Friday . About 24,000 wooden poles, 900 pylons, and 3,000 km of power lines were cut down. Some households would only find power after five to six weeks ( Figure 1 ). Such a weather-driven blackout was not the first to hit Québec province. On 13 March 1989, solar winds disrupted the Earth’s magnetic field, causing seven static var compensators (SVC) to disconnect from the grid in 1 min, due to excessive harmonics currents. Following the loss of the dynamic voltage support provided by the SVCs, the instability of the power system became inevitable. A major outage of the entire Québec network resulted, leaving 6 million people without power for 9–12 h.}, journal={IEEE Power and Energy Magazine}, author={Kamwa, Innocent and Liu, Ning}, year={2023}, month={May} } @article{sun_kong_wu_gao_chen_lu_2022, title={

DSM pricing method based on A3C and LSTM under cloud-edge environment

}, volume={315}, ISSN={["1872-9118"]}, DOI={10.1016/j.apenergy.2022.118853}, abstractNote={Demand-side management (DSM) could realize "peak cutting and valley filling" of power load and improve the stability and efficiency of power system. With the development of information systems, more smart devices are being deployed on the demand side. It has become a challenge for DSM service providers to take full use of the edge computing capacity and demand-side information to improve the accuracy of DSM decision-making, without revealing user privacy. This paper proposes a distributed DSM pricing method for service provider, based on asynchronous advantage actor-critic (A3C) algorithm and long short-term memory (LSTM) network under cloud-edge environment. The on-site utilization of user information is realized through distributed training and centralized decision-making structure of A3C algorithm. The training process is accelerated by LSTM based virtual environment, which greatly reduces the training cost of the algorithm. Case study results shows that the proposed method is able to make pricing decision for DSM service provider under cloud-edge environment. Moreover, through the combination of LSTM based virtual environment and A3C algorithm, the proposed method requires less historical data than other methods and improves the profit of service providers.}, journal={APPLIED ENERGY}, author={Sun, Fangyuan and Kong, Xiangyu and Wu, Jianzhong and Gao, Bixuan and Chen, Ke and Lu, Ning}, year={2022}, month={Jun} } @article{paduani_yu_xu_lu_2022, title={A Unified Power-Setpoint Tracking Algorithm for Utility-Scale PV Systems With Power Reserves and Fast Frequency Response Capabilities}, volume={13}, ISSN={["1949-3037"]}, url={https://doi.org/10.1109/TSTE.2021.3117688}, DOI={10.1109/TSTE.2021.3117688}, abstractNote={This paper presents a fast power-setpoint tracking algorithm to enable utility-scale photovoltaic (PV) systems to provide high quality grid services such as power reserves and fast frequency response. The algorithm unites maximum power-point estimation (MPPE) with flexible power-point tracking (FPPT) control to improve the performance of both algorithms, achieving fast and accurate PV power-setpoint tracking even under rapid solar irradiance changes. The MPPE is developed using a real-time, nonlinear curve-fitting approach based on the Levenberg-Marquardt algorithm. A modified adaptive FPPT based on the Perturb and Observe technique is developed for the power-setpoint tracking. By using MPPE to decouple the impact of irradiance changes on the measured PV output power, we develop a fast convergence technique for tracking power-reference changes within three FPPT iterations. Furthermore, to limit the maximum output power ripple, a new design is introduced for the steady-state voltage step size of the adaptive FPPT. The proposed algorithm is implemented on a testbed consisting of a 500 kVA three-phase, single-stage, utility-scale PV system on the OPAL-RT eMEGASIM platform. Results show that the proposed method outperforms the state-of-the-art.}, number={1}, journal={IEEE TRANSACTIONS ON SUSTAINABLE ENERGY}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Paduani, Victor Daldegan and Yu, Hui and Xu, Bei and Lu, Ning}, year={2022}, month={Jan}, pages={479–490} } @article{wu_ma_fu_hou_rehm_lu_2022, title={Design of a Battery Energy Management System for Capacity Charge Reduction}, volume={9}, ISSN={["2687-7910"]}, url={https://doi.org/10.1109/OAJPE.2022.3196690}, DOI={10.1109/OAJPE.2022.3196690}, abstractNote={This paper presents a novel dispatch and evaluation framework for battery energy storage systems (BESSs) to minimize a load servicing entity’s coincident demand during system peak hours. The framework consists of i) a two-step BESS dispatch process that accounts for uncertainties in forecasting system peak and using limited battery cycle life, and ii) procedures to design control parameters, determine BESS duration, and estimate the corresponding net benefits. In the proposed dispatch, a rule-based triggering mechanism is executed to determine whether to dispatch a BESS on an operating day by comparing the peak-day probability with a predetermined threshold. Once the dispatch is triggered, a model predictive control is carried out to maximize the expected reduction in peak demand. By exercising this two-step dispatch method with different thresholds, one can explore the trade-off between peak demand reduction effectiveness and loss of battery life, and thereby identify the optimal thresholds to maximize cumulative economic benefits. Case studies are conducted using the data provided by utilities in North Carolina. Simulation results are presented to demonstrate the effectiveness of the proposed method.}, journal={IEEE OPEN ACCESS JOURNAL OF POWER AND ENERGY}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Wu, Di and Ma, Xu and Fu, Tao and Hou, Zhangshuan and Rehm, P. J. and Lu, Ning}, year={2022}, pages={351–360} } @article{song_li_lu_2022, title={ProfileSR-GAN: A GAN Based Super-Resolution Method for Generating High-Resolution Load Profiles}, volume={13}, ISSN={["1949-3061"]}, url={https://doi.org/10.1109/TSG.2022.3158235}, DOI={10.1109/TSG.2022.3158235}, abstractNote={This paper presents a novel two-stage load profile super-resolution (LPSR) framework, ProfileSR-GAN, to upsample the low-resolution load profiles (LRLPs) to high-resolution load profiles (HRLPs). The LPSR problem is formulated as a Maximum-a-Posteriori problem. In the first-stage, a GAN-based model is adopted to restore high-frequency components from the LRLPs. To reflect the load-weather dependency, aside from the LRLPs, the weather data is added as an input to the GAN-based model. In the second-stage, a polishing network guided by outline loss and switching loss is novelly introduced to remove the unrealistic power fluctuations in the generated HRLPs and improve the point-to-point matching accuracy. To evaluate the realisticness of the generated HRLPs, a new set of load shape evaluation metrics is developed. Simulation results show that: i) ProfileSR-GAN outperforms the state-of-the-art methods in all shape-based metrics and can achieve comparable performance with those methods in point-to-point matching accuracy, and ii) after applying ProfileSR-GAN to convert LRLPs to HRLPs, the performance of a downstream task, non-intrusive load monitoring, can be significantly improved. This demonstrates that ProfileSR-GAN is an effective new mechanism for restoring high-frequency components in downsampled time-series data sets and improves the performance of downstream tasks that require HR load profiles as inputs.}, number={4}, journal={IEEE TRANSACTIONS ON SMART GRID}, author={Song, Lidong and Li, Yiyan and Lu, Ning}, year={2022}, month={Jul}, pages={3278–3289} } @article{wang_zhu_liang_meng_kling_lubkeman_lu_2021, title={A Data-driven Pivot-point-based Time-series Feeder Load Disaggregation Method}, ISSN={["1944-9925"]}, DOI={10.1109/PESGM46819.2021.9638034}, abstractNote={The load profile at a feeder-head is usually known to utility engineers while the nodal load profiles are not. However, the nodal load profiles are increasingly important for conducting time-series analysis in distribution systems. Therefore, in this paper, we present a pivot-point based, two-stage feeder load disaggregation algorithm using smart meter data. The two stages are load profile selection (LPS) and load profile allocation (LPA). In the LPS stage, a random load profile selection process is first executed to meet the load diversity requirement. Then, a few pairs of pivot points are selected as the matching targets. After that, a matching algorithm will run repetitively to select one load profile at a time for matching the reference load profile at the pivot points. In the LPA stage, the LPS selected load profiles are allocated to each load node on the feeder considering distribution transformer loading limits, load composition, and square-footage. The proposed method is validated using actual data collected in a North Carolina service area. Simulation results show that the proposed method can generate a unique load shape for each load node while match the shape of their aggregated profile with the actual feeder head load profile.}, journal={2021 IEEE POWER & ENERGY SOCIETY GENERAL MEETING (PESGM)}, author={Wang, Jiyu and Zhu, Xiangqi and Liang, Ming and Meng, Yao and Kling, Andrew and Lubkeman, David and Lu, Ning}, year={2021} } @article{hu_li_zhang_shirsat_muthukaruppan_tang_baran_lubkeman_lu_2021, title={A Load Switching Group based Feeder-level Microgrid Energy Management Algorithm for Service Restoration in Power Distribution System}, ISSN={["1944-9925"]}, DOI={10.1109/PESGM46819.2021.9638231}, abstractNote={This paper presents a load switching group based energy management system (LSG-EMS) for operating microgrids on a distribution feeder powered by one or multiple grid-forming distributed energy resources. Loads on a distribution feeder are divided into load switching groups that can be remotely switched on and off. The LSG-EMS algorithm, formulated as a mixed-integer linear programming (MILP) problem, has an objective function of maximizing the served loads while minimizing the total number of switching actions. A new set of topology constraints are developed for allowing multiple microgrids to be formed on the feeder and selecting the optimal supply path. Customer comfort is accounted for by maximizing the supply duration in the customer preferred service period and enforcing a minimum service duration. The proposed method is demonstrated on a modified IEEE 33-bus system using actual customer data. Simulation results show that the LSG-EMS successfully coordinates multiple grid-forming sources by selecting an optimal supply topology that maximizes the supply period of both the critical and noncritical loads while minimizing customer service interruptions in the service restoration process.}, journal={2021 IEEE POWER & ENERGY SOCIETY GENERAL MEETING (PESGM)}, author={Hu, Rongxing and Li, Yiyan and Zhang, Si and Shirsat, Ashwin and Muthukaruppan, Valliappan and Tang, Wenyuan and Baran, Mesut and Lubkeman, David and Lu, Ning}, year={2021} } @article{alrushoud_mcentee_lu_2021, title={A Zonal Volt/VAR Control Mechanism for High PV Penetration Distribution Systems}, ISSN={["1944-9925"]}, DOI={10.1109/PESGM46819.2021.9637841}, abstractNote={This paper presents a zonal Volt/VAR control scheme for regulating voltage in unbalanced 3-phase distribution systems using inverter-based resources (IBR). First, the dependency between nodal voltage changes and IBR reactive power injections is derived via voltage sensitivity studies. Then, a fast-incremental clustering method is used to divide the distribution circuit into weakly-coupled zones based on correlations between nodal voltage sensitivities. The weak-coupling allows the voltage to be regulated independently within each zone using a rule-based voltage controller to dispatch IBR for voltage corrections. Simulation results on actual distribution feeder show that the proposed zone-based Volt/VAR control method maintains system voltages within their operational limits while reducing the runtime of the Volt/VAR controller from tens of second to a couple of milliseconds compared with centralized, optimization-based Volt/VAR control methods.}, journal={2021 IEEE POWER & ENERGY SOCIETY GENERAL MEETING (PESGM)}, author={Alrushoud, Asmaa and McEntee, Catie and Lu, Ning}, year={2021} } @article{li_zhang_hu_lu_2021, title={A meta-learning based distribution system load forecasting model selection framework}, volume={294}, ISSN={["1872-9118"]}, DOI={10.1016/j.apenergy.2021.116991}, abstractNote={This paper presents a meta-learning based, automatic distribution system load forecasting model selection framework. The framework includes the following processes: feature extraction, candidate model preparation and labeling, offline training, and online model recommendation. Using load forecasting needs and data characteristics as input features, multiple metalearners are used to rank the candidate load forecast models based on their forecasting accuracy. Then, a scoring-voting mechanism is proposed to weights recommendations from each meta-leaner and make the final recommendations. Heterogeneous load forecasting tasks with different temporal and technical requirements at different load aggregation levels are set up to train, validate, and test the performance of the proposed framework. Simulation results demonstrate that the performance of the meta-learning based approach is satisfactory in both seen and unseen forecasting tasks.}, journal={APPLIED ENERGY}, author={Li, Yiyan and Zhang, Si and Hu, Rongxing and Lu, Ning}, year={2021}, month={Jul} } @article{xie_mcentee_zhang_mather_lu_2021, title={Development of an Encoding Method on a Co-Simulation Platform for Mitigating the Impact of Unreliable Communication}, volume={12}, ISSN={["1949-3061"]}, url={https://doi.org/10.1109/TSG.2020.3039949}, DOI={10.1109/TSG.2020.3039949}, abstractNote={This article presents a hardware-in-the-loop (HIL) based modeling approach for simulating impacts of unreliable communication on the performance of centralized volt-var control and for developing an encoding method to mitigate the impacts. First, an asynchronous real-time HIL simulation platform is introduced to enable multi-rate co-simulation of a distribution system with many inverter-based distributed energy resources (DERs). The distribution system is modeled by milliseconds phasor-based models and the DERs are modeled by micro-seconds power electronic models. Communication connections between a centralized volt-var controller (modeled externally to the HIL testbed) and smart inverters are built by implementing Modbus links and the Long Term Evolution network. On this co-simulation platform, an enhanced, augmented Lagrangian multiplier based encoded data recovery (EALM-EDR) algorithm for mitigating the impact of unreliable communication is developed and validated. Simulation results demonstrate the efficacy of using the HIL-based co-simulation platform as a power grid digital twin for developing algorithms that coordinate a large number of heterogeneous control systems through wired and wireless communication links.}, number={3}, journal={IEEE TRANSACTIONS ON SMART GRID}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Xie, Fuhong and McEntee, Catie and Zhang, Mingzhi and Mather, Barry and Lu, Ning}, year={2021}, month={May}, pages={2496–2507} } @article{long_yu_xie_lu_lubkeman_2021, title={Diesel Generator Model Parameterization for Microgrid Simulation Using Hybrid Box-Constrained Levenberg-Marquardt Algorithm}, volume={12}, ISSN={["1949-3061"]}, url={https://doi.org/10.1109/TSG.2020.3026617}, DOI={10.1109/TSG.2020.3026617}, abstractNote={Existing generator parameterization methods, typically developed for large turbine generator units, are difficult to apply to small kW-level diesel generators in microgrid applications. This article presents a model parameterization method that estimates a complete set of kW-level diesel generator parameters simultaneously using only load-step-change tests with limited measurement points. This method provides a more cost-efficient and robust approach to achieve high-fidelity modeling of diesel generators for microgrid dynamic simulation. A two-stage hybrid box-constrained Levenberg-Marquardt (H-BCLM) algorithm is developed to search the optimal parameter set given the parameter bounds. A heuristic algorithm, namely Generalized Opposition-based Learning Genetic Algorithm (GOL-GA), is applied to identify proper initial estimates at the first stage, followed by a modified Levenberg-Marquardt algorithm designed to fine tune the solution based on the first-stage result. The proposed method is validated against dynamic simulation of a diesel generator model and field measurements from a 16kW diesel generator unit.}, number={2}, journal={IEEE TRANSACTIONS ON SMART GRID}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Long, Qian and Yu, Hui and Xie, Fuhong and Lu, Ning and Lubkeman, David}, year={2021}, month={Mar}, pages={943–952} } @article{nguyen_ogle_fan_ke_vallem_samaan_lu_2021, title={EMS and DMS Integration of the Coordinative Real-time Sub-Transmission Volt-Var Control Tool under High DER Penetration}, ISSN={["1944-9925"]}, DOI={10.1109/PESGM46819.2021.9638160}, abstractNote={This paper proposes an applicable approach to deploy the Coordinative Real-time Sub-Transmission Volt-Var Control Tool (CReST-VCT), and a holistic system integration framework considering both the energy management system (EMS) and distribution system management system (DMS). This provides an architectural basis and can serve as the implementation guideline of CReST-VCT and other advanced grid support tools, to co-optimize the operation benefits of distributed energy resources (DERs) and assets in both transmission and distribution networks. Potential communication protocols for different physical domains of a real application is included. Performance and security issues are also discussed, along with specific considerations for field deployment. Finally, the paper presents a viable pathway for CReST-VCT and other advanced grid support tools to be integrated in an open-source standardized-based platform that supports distribution utilities.}, journal={2021 IEEE POWER & ENERGY SOCIETY GENERAL MEETING (PESGM)}, author={Nguyen, Quan and Ogle, Jim and Fan, Xiaoyuan and Ke, Xinda and Vallem, Mallikarjuna R. and Samaan, Nader and Lu, Ning}, year={2021} } @article{liang_meng_wang_lubkeman_lu_2021, title={FeederGAN: Synthetic Feeder Generation via Deep Graph Adversarial Nets}, volume={12}, ISSN={["1949-3061"]}, url={https://doi.org/10.1109/TSG.2020.3025259}, DOI={10.1109/TSG.2020.3025259}, abstractNote={This article presents a novel, automated, generative adversarial networks (GAN) based synthetic feeder generation mechanism, abbreviated as FeederGAN. FeederGAN digests real feeder models represented by directed graphs via a deep learning framework powered by GAN and graph convolutional networks (GCN). Information of a distribution feeder circuit is extracted from its model input files so that the device connectivity is mapped onto the adjacency matrix and the device characteristics, such as circuit types (i.e., 3-phase, 2-phase, and 1-phase) and component attributes (e.g., length and current ratings), are mapped onto the attribute matrix. Then, Wasserstein distance is used to optimize the GAN and GCN is used to discriminate the generated graphs from the actual ones. A greedy method based on graph theory is developed to reconstruct the feeder using the generated adjacency and attribute matrices. Our results show that the GAN generated feeders resemble the actual feeder in both topology and attributes verified by visual inspection and by empirical statistics obtained from actual distribution feeders.}, number={2}, journal={IEEE TRANSACTIONS ON SMART GRID}, author={Liang, Ming and Meng, Yao and Wang, Jiyu and Lubkeman, David L. and Lu, Ning}, year={2021}, month={Mar}, pages={1163–1173} } @article{liang_meng_wang_lubkeman_lu_2021, title={FeederGAN: Synthetic Feeder Generation via Deep Graph Adversarial Nets}, ISSN={["1944-9925"]}, DOI={10.1109/PESGM46819.2021.9638247}, abstractNote={This paper presents a novel, automated, generative adversarial networks (GAN) based synthetic feeder generation mechanism, abbreviated as FeederGAN. FeederGAN digests real feeder models represented by directed graphs via a deep learning framework powered by GAN and graph convolutional networks (GCN). Information of a distribution feeder circuit is extracted from its model input files so that the device connectivity is mapped onto the adjacency matrix and the device characteristics, such as circuit types (i.e., 3-phase, 2-phase, and 1-phase) and component attributes (e.g., length and current ratings), are mapped onto the attribute matrix. Then, Wasserstein distance is used to optimize the GAN and GCN is used to discriminate the generated graphs from the actual ones. A greedy method based on graph theory is developed to reconstruct the feeder using the generated adjacency and attribute matrices. Our results show that the GAN generated feeders resemble the actual feeder in both topology and attributes verified by visual inspection and by empirical statistics obtained from actual distribution feeders.}, journal={2021 IEEE POWER & ENERGY SOCIETY GENERAL MEETING (PESGM)}, author={Liang, Ming and Meng, Yao and Wang, Jiyu and Lubkeman, David and Lu, Ning}, year={2021} } @article{shirsat_muthukaruppan_hu_lu_baran_lubkeman_tang_2021, title={Hierarchical Multi-timescale Framework For Operation of Dynamic Community Microgrid}, ISSN={["1944-9925"]}, DOI={10.1109/PESGM46819.2021.9638104}, abstractNote={Distribution system integrated community microgrids (CMGs) can restore loads during extended outages. The CMG is challenged with limited resource availability, absence of a robust grid-support, and demand-supply uncertainty. To address these challenges, this paper proposes a three-stage hierarchical multi-timescale framework for scheduling and real-time (RT) dispatch of CMGs. The CMG's ability to dynamically expand its boundary to support the neighboring grid sections is also considered. The first stage solves a stochastic day-ahead (DA) scheduling problem to obtain referral plans for optimal resource rationing. The intermediate near real-time scheduling stage updates the DA schedule closer to the dispatch time, followed by the RT dispatch stage. The proposed methodology is validated via numerical simulations on a modified IEEE 123-bus system, which shows superior performance in terms of RT load supplied under different forecast error cases, outage duration scenarios, and against the traditionally used two-stage approach.}, journal={2021 IEEE POWER & ENERGY SOCIETY GENERAL MEETING (PESGM)}, author={Shirsat, Ashwin and Muthukaruppan, Valliappan and Hu, Rongxing and Lu, Ning and Baran, Mesut and Lubkeman, David and Tang, Wenyuan}, year={2021} } @article{lu_2021, title={Load Control A new era of intelligent automation}, volume={9}, ISSN={["2325-5889"]}, url={https://doi.org/10.1109/MELE.2021.3093596}, DOI={10.1109/MELE.2021.3093596}, abstractNote={Imagine that we traveled into the future where more than 50% of electricity production is generated by wind and solar. Will you wonder how the grid will operate in an overcast, windless, extremely cold/hot day, where half of its generation fleet may become unavailable?}, number={3}, journal={IEEE ELECTRIFICATION MAGAZINE}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Lu, Ning}, year={2021}, month={Sep}, pages={18–28} } @article{long_liao_chong_rodriguez_guerrero_2021, title={MPC-Controlled Virtual Synchronous Generator to Enhance Frequency and Voltage Dynamic Performance in Islanded Microgrids}, url={https://doi.org/10.1109/TSG.2020.3027051}, DOI={10.1109/TSG.2020.3027051}, abstractNote={The use of high penetration converter-interfaced renewable energy (RE) based microgrids (MGs), due to the absence of rotational masses from conventional synchronous generators (SGs), may lead to a lack of inertia, which may lead the steeper frequency and voltage fluctuations that may in turn cause instability issues and challenges the normal operation of sensitive loads. To suppress these fluctuations and enhance the MGs stability, a novel model predictive control (MPC)-controlled virtual synchronous generator (VSG) for an energy storage system (ESS) is introduced. The proposed method can provide inertia support during transient states and enhance the dynamic characteristics of system voltage and frequency. By establishing the prediction model of VSG and designing the cost function for frequency and power, the increments of the needed active and reactive power are calculated then superposed on the power reference of VSG. The results show that the suppression performance of the voltage and frequency variations under loading transition with the proposed method is better than those of other techniques. Simulation and hardware-in-the-loop (HIL) results further demonstrate the effectiveness of the proposed method.}, journal={IEEE Transactions on Smart Grid}, author={Long, Bo and Liao, Yong and Chong, Kil To and Rodriguez, Jose and Guerrero, Josep M.}, year={2021}, month={Mar} } @article{paduani_song_xu_lu_2021, title={Maximum Power Reference Tracking Algorithm for Power Curtailment of Photovoltaic Systems}, ISSN={["1944-9925"]}, DOI={10.1109/PESGM46819.2021.9638157}, abstractNote={This paper presents an algorithm for power curtailment of photovoltaic (PV) systems under fast solar irradiance intermittency. Based on the Perturb and Observe (P&O) technique, the method contains an adaptive gain that is compensated in real-time to account for moments of lower power availability. In addition, an accumulator is added to the calculation of the step size to reduce the overshoot caused by large irradiance swings. A testbed of a three-phase single-stage, 500 kVA PV system is developed on the OPAL-RT eMEGAsim real-time simulator. Field irradiance data and a regulation signal from PJM (RTO) are used to compare the performance of the proposed method with other techniques found in the literature. Results indicate an operation with smaller overshoot, less dc-link voltage oscillations, and improved power reference tracking capability.}, journal={2021 IEEE POWER & ENERGY SOCIETY GENERAL MEETING (PESGM)}, author={Paduani, Victor and Song, Lidong and Xu, Bei and Lu, Ning}, year={2021} } @article{xie_mcentee_zhang_lu_ke_vattern_samaan_2021, title={Networked HIL Simulation System for Modeling Large-scale Power Systems}, ISSN={["2163-4939"]}, DOI={10.1109/NAPS50074.2021.9449646}, abstractNote={This paper presents a networked hardware-in-the-loop (HIL) simulation system for modeling large-scale power systems. Researchers have developed many HIL test systems for power systems in recent years. Those test systems can model both microsecond-level dynamic responses of power electronic systems and millisecond-level transients of transmission and distribution grids. By integrating individual HIL test systems into a network of HIL test systems, we can create large-scale power grid digital twins with flexible structures at required modeling resolution that fits for a wide range of system operating conditions. This will not only significantly reduce the need for field tests when developing new technologies but also greatly shorten the model development cycle. In this paper, we present a networked OPAL-RT based HIL test system for developing transmission-distribution coordinative Volt-VAr regulation technologies as an example to illustrate system setups, communication requirements among different HIL simulation systems, and system connection mechanisms. Impacts of communication delays, information exchange cycles, and computing delays are illustrated. Simulation results show that the performance of a networked HIL test system is satisfactory.}, journal={2020 52ND NORTH AMERICAN POWER SYMPOSIUM (NAPS)}, author={Xie, Fuhong and McEntee, Catie and Zhang, Mingzhi and Lu, Ning and Ke, Xinda and Vattern, Mallikarjuna R. and Samaan, Nader}, year={2021} } @article{kong_zhang_lu_ma_li_2021, title={Online Smart Meter Measurement Error Estimation Based on EKF and LMRLS Method}, volume={12}, url={https://doi.org/10.1109/TSG.2021.3077693}, DOI={10.1109/TSG.2021.3077693}, abstractNote={This paper presents an online smart meter measurement error estimation algorithm. Extended Kalman filter (EKF) and limit memory recursive least square (LMRLS) methods are used for remote calibration of a large amount of user-side smart meters. Then, a modified joint estimation model is obtained by selecting the estimation step that conforms to the actual working condition and filtering the abnormal estimation value according to the line loss rate characteristics. Finally, based on the experimental data obtained by the program-controlled load simulation system, the precision of metering error estimation is verified. The results show that the method improves the precision of error estimation by analyzing the coupling between line loss rates and metering error estimation. By using the limited memory RLS algorithm, the influence of old measured data on error parameter estimation is reduced so that new data can be added to correct error parameter estimation to enhance the precision of the real-time smart meter error estimation.}, number={5}, journal={IEEE Transactions on Smart Grid}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Kong, Xiangyu and Zhang, Xiaopeng and Lu, Ning and Ma, Yuying and Li, Ye}, year={2021}, month={Sep}, pages={4269–4279} } @article{wang_huang_wu_lu_2021, title={Operating a Commercial Building HVAC Load as a Virtual Battery Through Airflow Control}, volume={12}, url={https://doi.org/10.1109/TSTE.2020.2988513}, DOI={10.1109/TSTE.2020.2988513}, abstractNote={Virtual battery (VB) is an innovative method to model flexibility of building loads and effectively coordinate them with other resources at a system level. Unlike a real battery with a dedicated power conversion system for charging control, methods are required for operating building loads to deviate from the baseline to respond to grid signals. This article presents a VB control for a commercial heating, ventilation, and air conditioning (HVAC) system to follow the desired power consumption in real-time by adjusting zonal airflow rates. The proposed method consists of two parts. At the system level, a mixed feedforward and feedback control is used to estimate the desired total airflow rate. At the zone level, two priority-based algorithms are then proposed to distribute the total airflow rate to individual zones. In particular, a zonal airflow limit estimation method is proposed using machine-learning techniques, in contrast to physics-based thermal models in existing studies, to more accurately capture zonal thermal dynamics and improve temperature control performance. An office building on the Pacific Northwest National Laboratory campus is implemented in EnergyPlus, and used to illustrate and validate the proposed control.}, number={1}, journal={IEEE Transactions on Sustainable Energy}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Wang, Jiyu and Huang, Sen and Wu, Di and Lu, Ning}, year={2021}, month={Jan}, pages={158–168} } @article{meng_yu_lu_shi_2021, title={Time Series Classification for Locating Forced Oscillation Sources}, volume={12}, ISSN={["1949-3061"]}, url={https://doi.org/10.1109/TSG.2020.3028188}, DOI={10.1109/TSG.2020.3028188}, abstractNote={This article presents a machine learning based time-series classification method for using synchrophasor measurements to locate the source of forced oscillation (FO) for fast disturbance removal. First, multivariate time series (MTS) matrices are constructed by the most informative measurements selected by sequential feature selection from each power plant. Then, the Mahalanobis matrix is trained such that the Mahalanobis distance between the MTSs from the same class (i.e., with the same FO source location) are minimized and from different classes (i.e., with different FO source locations) are maximized. This allows MTSs to be classified by classifiers with class membership corresponding to the location of each FO source. To meet the runtime requirements of online matching, class templates are constructed to reduce data size and improve matching efficiency. To account for uncertainty in identifying the exact beginning of an FO event, dynamic time warping is used to align the out-of-sync MTSs. IEEE 39bus and WECC 179bus systems are used for algorithm development and validation. Simulation results demonstrate that the algorithm meets online operation runtime requirement with high accuracy using misaligned data sets.}, number={2}, journal={IEEE TRANSACTIONS ON SMART GRID}, author={Meng, Yao and Yu, Zhe and Lu, Ning and Shi, Di}, year={2021}, month={Mar}, pages={1712–1721} } @article{bakhshi-jafarabadi_sadeh_jesus chavez_popov_2021, title={Two-Level Islanding Detection Method for Grid-Connected Photovoltaic System-Based Microgrid With Small Non-Detection Zone}, url={https://doi.org/10.1109/TSG.2020.3035126}, DOI={10.1109/TSG.2020.3035126}, abstractNote={This article proposes a fast and reliable two-level islanding detection method (IDM) for grid-connected photovoltaic system (GCPVS)-based microgrid. In the first level of the proposed IDM, the magnitude of the rate of change of output voltage (ROCOV) is computed. If this variable exceeds a predefined threshold, a disturbance is injected into the duty cycle of DC/DC converter after a given time delay to deviate the system operating point away of its maximum power point (MPP) condition. This leads to a substantial active power output and voltage reduction in an islanded mode. Therefore, the ROCOV and the rate of change of active power output (ROCOP) indices, measured in the second stage, pose great negative sets at the same time in islanding states. However, the variation of at least one of these variables is near-zero in non-islanding switching events. The assessment of the presented algorithm has been conducted under extensive islanding and non-islanding scenarios for a case study system with two PV power plants using hardware-in-the-loop (HiL) simulation tests. The provided results remark precise islanding classification with an eminently small non-detection zone (NDZ) within 510 ms. The presented IDM has the advantages of self-standing thresholds determination, no improper effect on the output power quality, and simple and inexpensive structure. Moreover, the fast MPP restoration of the proposed scheme after islanding identification boosts the chance of seamless reconnection and DG autonomous operation in microgrid.}, journal={IEEE Transactions on Smart Grid}, author={Bakhshi-Jafarabadi, Reza and Sadeh, Javad and Jesus Chavez, Jose and Popov, Marjan}, year={2021}, month={Mar} } @article{wang_zhu_liang_meng_kling_lubkeman_lu_2020, title={A Data-Driven Pivot-Point-Based Time-Series Feeder Load Disaggregation Method}, volume={11}, url={https://doi.org/10.1109/TSG.2020.3008603}, DOI={10.1109/TSG.2020.3008603}, abstractNote={The load profile at a feeder-head is usually known to utility engineers while the nodal load profiles are not. However, the nodal load profiles are increasingly important for conducting time-series analysis in distribution systems. Therefore, in this paper, we present a pivot-point based, two-stage feeder load disaggregation algorithm using smart meter data. The two stages are load profile selection (LPS) and load profile allocation (LPA). In the LPS stage, a random load profile selection process is first executed to meet the load diversity requirement. Then, a few pairs of pivot points are selected as the matching targets. After that, a matching algorithm will run repetitively to select one load profile at a time for matching the reference load profile at the pivot points. In the LPA stage, the LPS selected load profiles are allocated to each load node on the feeder considering distribution transformer loading limits, load composition, and square-footage. The proposed method is validated using actual data collected in a North Carolina service area. Simulation results show that the proposed method can generate a unique load shape for each load node while match the shape of their aggregated profile with the actual feeder head load profile.}, number={6}, journal={IEEE Transactions on Smart Grid}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Wang, Jiyu and Zhu, Xiangqi and Liang, Ming and Meng, Yao and Kling, Andrew and Lubkeman, David L. and Lu, Ning}, year={2020}, month={Nov}, pages={5396–5406} } @article{xie_yu_long_zeng_lu_2020, title={Battery Model Parameterization Using Manufacturer Datasheet and Field Measurement for Real-Time HIL Applications}, volume={11}, url={https://doi.org/10.1109/TSG.2019.2953718}, DOI={10.1109/TSG.2019.2953718}, abstractNote={This paper presents a novel battery model parameterization method using actual field measurement and manufacturer datasheet for real-time hardware-in-the-loop (HIL) applications. It is critical that real-time HIL models can accurately reproduce field test results so that tests can be conducted on HIL testbeds instead of in the field. In the past, numerical heuristic optimization algorithms were often used to derive parameters for battery models. However, the deterministic algorithms often reach a locally optimal solution and stochastic heuristic searching strategies suffer from low searching efficiency. Therefore, in this paper, we propose a global-local searching enhanced genetic algorithm (GL-SEGA). By applying the generalized opposition-based learning mechanism, GL-SEGA can efficiently explore the global solution space. By using the trust-region-reflective method to perform the local search, the GL-SEGA can improve the accuracy and convergence in its local exploitations. Field measurements and manufactory datasheets are used to test and validate the accuracy and robustness of the GL-SEGA algorithm.}, number={3}, journal={IEEE Transactions on Smart Grid}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Xie, Fuhong and Yu, Hui and Long, Qian and Zeng, Wente and Lu, Ning}, year={2020}, month={May}, pages={2396–2406} } @article{li_du_lu_2020, title={PFR ancillary service in low-inertia power system}, volume={14}, ISSN={["1751-8695"]}, DOI={10.1049/iet-gtd.2019.1536}, abstractNote={A high level of renewable resource penetration could lead to displacement of conventional synchronous generators from dispatch, and consequently, reduce the system inertia. The decline in the system inertia will increase the primary frequency response (PFR) need requiring to maintain grid frequency stability. This study proposes a new market design to co-optimise energy, inertia and PFR while considering uncertainties in renewable energy productions. A full dynamic model of Electric Reliability Council of Texas (ERCOT) interconnection is used to quantify the PFR requirement for the system inertia. The proposed method explicitly incorporates frequency dynamics and uncertainties in energy production from renewable resources in the scheduling process, which is formulated as a stochastic unit commitment problem. A case study of ERCOT grid demonstrated that the proposed stochastic scheduling of energy, inertia and PFR could yield a more cost-effective solution than the traditional deterministic formulation for the grids with a high penetration of renewable resources.}, number={5}, journal={IET GENERATION TRANSMISSION & DISTRIBUTION}, author={Li, Weifeng and Du, Pengwei and Lu, Ning}, year={2020}, month={Mar}, pages={920–930} } @article{lu_hong_2020, title={Utility Rate Making: An Intersection of Economics and Social Good [Guest Editorial]}, volume={18}, url={https://doi.org/10.1109/MPE.2020.2972665}, DOI={10.1109/MPE.2020.2972665}, abstractNote={Utility rate making is becoming increasingly critical. The high penetration of distributed energy resources changes not only the landscape of utility operating and planning practices but also the business models that govern how utilities recover their service costs. The objective of power generation and delivery has changed from considering only the delivery of reliable and cost-effective energy services to also accounting for sustainability and minimizing adverse environmental impacts. Today’s energy systems are evolving from traditional highly centralized suppliers to multiple distributed small suppliers or even self-suppliers. This evolution could be further accelerated when major technology breakthroughs in energy storage and photovoltaics (PVs) make these systems less expensive, more reliable, and more efficient. All of these electric system changes greatly affect many traditional rate-making principles, methodologies, and processes.}, number={3}, journal={IEEE Power and Energy Magazine}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Lu, Ning and Hong, Tao}, year={2020}, month={May}, pages={14–16} } @article{ke_wu_lu_2019, title={A Real-Time Greedy-Index Dispatching Policy for Using PEVs to Provide Frequency Regulation Service}, volume={10}, ISSN={["1949-3061"]}, DOI={10.1109/TSG.2017.2754241}, abstractNote={This paper presents a real-time greedy-index dispatching policy (GIDP) for using plug-in electric vehicles (PEVs) to provide frequency regulation services. A new service cost allocation mechanism is proposed to award PEVs based on the amount of service they provided, while considering compensations for delayed-charging and reduction of battery lifetime due to participation of the service. The GIDP transforms the optimal dispatch problem from a high-dimensional space into an 1-D space while preserving the solution optimality. When solving the transformed problem in real-time, the global optimality of the GIDP solution can be guaranteed by mathematically proved “indexability.” Because the GIDP index can be calculated upon the PEV’s arrival and used for the entire decision making process till its departure, the computational burden is minimized and the complexity of the aggregator dispatch process is significantly reduced. Simulation results are used to evaluate the proposed GIDP, and to demonstrate the potential profitability from providing frequency regulation service by using PEVs.}, number={1}, journal={IEEE TRANSACTIONS ON SMART GRID}, author={Ke, Xinda and Wu, Di and Lu, Ning}, year={2019}, month={Jan}, pages={864–877} } @article{henri_lu_2019, title={A Supervised Machine Learning Approach to Control Energy Storage Devices}, volume={10}, ISSN={["1949-3061"]}, DOI={10.1109/TSG.2019.2892586}, abstractNote={This paper introduces a supervised machine learning (ML) approach to predict and schedule the real-time operation mode of the next operation interval for residential PV/battery systems controlled by mode-based controllers. The performance of the mode-based economic model-predictive control approach is used as the benchmark. The residential load and PV data used in this paper are 1-min data downloaded from the Pecan Street Project website. The optimal operation mode for each control interval is first derived from the historical data used as the training set. Then, four ML algorithms (i.e., neural network, support vector machine, logistic regression, and random forest algorithms) are applied. We compared the performance of the four algorithms when using different number of features and length of the training sets extracted from different months of the year. Simulation results show that using the ML approach can effectively improve the performance of the mode-based control system and reduce the computation effort of local controllers because the training can be completed on a cloud-based ML engine. The work presented in this paper paves the way for using a shared-learning platform to design controllers of residential PV/storage systems. This may significantly reduce the cost for implementing such systems.}, number={6}, journal={IEEE TRANSACTIONS ON SMART GRID}, author={Henri, Gonzague and Lu, Ning}, year={2019}, month={Nov}, pages={5910–5919} } @article{henri_lu_carrejo_2019, title={Mode-based energy storage control approach for residential photovoltaic systems}, volume={2}, ISSN={2515-2947}, url={http://dx.doi.org/10.1049/IET-STG.2018.0159}, DOI={10.1049/IET-STG.2018.0159}, abstractNote={This study presents a novel mode-based energy storage control approach. Assuming that an energy storage device (ESD) is equipped with a set of predetermined real-time control modes, the dispatch objective is to select an optimal mode instead of a continuous charging or discharging power value. A two-stage algorithm is developed for mode selection. In the first stage, a sliding 24 h economic model predictive control algorithm is used to determine the power outputs of the ESD for the next 24 h. In the second stage, the output sign for the next time step determines the class of modes to be elected (charging or discharging). The information from the first stage is used to compute the total cost for each selected mode. The mode with the lowest day-ahead cost is chosen. The residential electricity consumption data collected in the PECAN Street Project is used in the simulation to validate the performance of the proposed algorithm. Simulation results show that using a mode-based approach reduces the sensitivity to forecasting errors along with load and solar variability. The algorithm performance is consistent across different load patterns.}, number={1}, journal={IET Smart Grid}, publisher={Institution of Engineering and Technology (IET)}, author={Henri, Gonzague and Lu, Ning and Carrejo, Carlos}, year={2019}, month={Mar}, pages={69–76} } @article{zhu_lu_zheng_sun_mei_2019, title={Optimal day-ahead scheduling for commercial building-level consumers under TOU and demand pricing plan}, volume={173}, ISSN={["1873-2046"]}, DOI={10.1016/j.epsr.2019.04.012}, abstractNote={In this paper, we solve the day-ahead scheduling programming problem for commercial building-level consumers with combined time-of-use ($/kWh) and demand ($/kW) pricing plans. Aiming at minimizing the monthly charge, the problem formulation is proposed as a generic algorithm that produces day-ahead building operation schedules. It considers the influences of daily peak load during on-peak hours and daily energy consumption on the monthly charge. The aggregation model of building-level space conditionings is built for scheduling demo. To obtain the near global optimum, a multi sub-swarms particle swarm optimization (MSPSO) is proposed by introducing the ideas of mutation operation, work hierarchy and iterative regrouping into particle swarm optimization (PSO). It improves the population diversity for enhancing the global searching ability and the ability of escaping from local optimum. The PSO comparison shows that MSPSO has better convergence performance with higher stability compared with some classical PSOs. Furthermore, a commercial office-style building with space conditionings is simulated. Using TOU and demand pricing plan from Duke Energy, numerical results demonstrate that the proposed day-ahead scheduling algorithm and the improved MSPSO can reduce the monthly charge by 30% and 17%, respectively.}, journal={ELECTRIC POWER SYSTEMS RESEARCH}, author={Zhu, Kedong and Lu, Ning and Zheng, Jianyong and Sun, Guoqiang and Mei, Fei}, year={2019}, month={Aug}, pages={240–250} } @article{de queiroz_mulcahy_sankarasubramanian_deane_mahinthakumar_lu_decarolis_2019, title={Repurposing an energy system optimization model for seasonal power generation planning}, volume={181}, ISSN={0360-5442}, url={http://dx.doi.org/10.1016/j.energy.2019.05.126}, DOI={10.1016/j.energy.2019.05.126}, abstractNote={Seasonal climate variations affect electricity demand, which in turn affects month-to-month electricity planning and operations. Electricity system planning at the monthly timescale can be improved by adapting climate forecasts to estimate electricity demand and utilizing energy models to estimate monthly electricity generation and associated operational costs. The objective of this paper is to develop and test a computationally efficient model that can support seasonal planning while preserving key aspects of system operation over hourly and daily timeframes. To do so, an energy system optimization model is repurposed for seasonal planning using features drawn from a unit commitment model. Different scenarios utilizing a well-known test system are used to evaluate the errors associated with both the repurposed energy system model and an imperfect load forecast. The results show that the energy system optimization model using an imperfect load forecast produces differences in monthly cost and generation levels that are less than 2% compared with a unit commitment model using a perfect load forecast. The enhanced energy system optimization model can be solved approximately 100 times faster than the unit commitment model, making it a suitable tool for future work aimed at evaluating seasonal electricity generation and demand under uncertainty.}, journal={Energy}, publisher={Elsevier BV}, author={de Queiroz, A.R. and Mulcahy, D. and Sankarasubramanian, A. and Deane, J.P. and Mahinthakumar, G. and Lu, N. and DeCarolis, J.F.}, year={2019}, month={Aug}, pages={1321–1330} } @article{zhu_wang_lu_samaan_huang_ke_2018, title={A Hierarchical VLSM-Based Demand Response Strategy for Coordinative Voltage Control between Transmission and Distribution Systems}, ISSN={1949-3053 1949-3061}, url={http://dx.doi.org/10.1109/tsg.2018.2869367}, DOI={10.1109/tsg.2018.2869367}, abstractNote={This paper presents a two-stage hierarchical voltage-load sensitivity matrix (VLSM)-based demand response (DR) algorithm for regulating the voltage at distribution feeders while fulfilling the transmission system DR requests. This allows distributed energy resources to be aggregated to provide transmission-level services without causing operational issues in the distribution grids. At the beginning of each operation interval, a transmission system controller will issue DR commands to distribution system controllers. In the first stage, the distribution system controller uses a VLSM-based dispatch algorithm to dispatch the available DR resources on the distribution feeder with an objective to minimize the total voltage deviations at the lowest cost. Then, power flow studies are conducted assuming that the DR commands have been executed. If voltage violations are detected, a second-stage VLSM-based DR dispatch is performed to remove those violations. After that, the upper and lower DR limits calculated for the next operation interval are sent back to the transmission system controller so the transmission optimization algorithm can use them as operational constraints to make subsequent decisions. The DR resources include smart photovoltaic (PV) inverters that can curtail real power and provide reactive power support, controllable loads and capacitor banks. The IEEE 123-bus test system with 5-min PV and load data is used to evaluate the performance of the algorithm. Simulation results show that the proposed algorithm can fulfill the transmission-level DR requests while maintaining the voltage in the distribution system within limits.}, journal={IEEE Transactions on Smart Grid}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Zhu, Xiangqi and Wang, Jiyu and Lu, Ning and Samaan, Nader and Huang, Renke and Ke, Xinda}, year={2018}, pages={1–1} } @inproceedings{henri_lu_carreio_2018, title={A Machine Learning Approach for Real-time Battery Optimal Operation Mode Prediction and Control}, ISBN={9781538655832}, url={http://dx.doi.org/10.1109/tdc.2018.8440141}, DOI={10.1109/tdc.2018.8440141}, abstractNote={This paper introduces a machine learning approach for real-time battery optimal operation mode prediction in residential PV applications. First, from the historical data, the optimal battery operation mode for each operation interval is derived. Then, a best performing algorithm for the prediction of the optimal modes is obtained. Performances are tested with different number of features in the training test and different training lengths. Then, the features will be used to predict future operation mode in real-time operations. A comparison on bill savings is made with the model-predictive control approach using the residential load and PV data from the Pecan Street project website under the Hawaiian electricity rate. Simulation results show a 9 points improvement in performance.}, booktitle={2018 IEEE/PES Transmission and Distribution Conference and Exposition (T&D)}, publisher={IEEE}, author={Henri, Gonzague and Lu, Ning and Carreio, Carlos}, year={2018}, month={Apr} } @inproceedings{henri_lu_2018, title={A Multi-Agent Shared Machine Learning Approach for Real-time Battery Operation Mode Prediction and Control}, ISBN={9781538677032}, url={http://dx.doi.org/10.1109/pesgm.2018.8585907}, DOI={10.1109/pesgm.2018.8585907}, abstractNote={This paper introduces a machine learning approach for real-time battery operation mode prediction and control for residential PV applications. The novelty resides in the shared learning process among the devices. All the ESDs will share their historical data with a learning aggregator in order to train a ML algorithm for the mode prediction. The learning aggregator will then send the trained algorithm back to the agents. Its role will be to train and maintain the ML algorithm. First, from the historical data, the optimal battery operation mode for each operation time step is derived. Performances are tested with different number of houses in the training test and different training lengths. The month of August is reserved for testing, while the rest of year is used for training. In the first scenario, the same houses used in the training are used in the testing. In the second scenario, one set of houses is used for training and the other set for testing. Then, the shared-algorithm will be used to predict future operation mode for real-time operation. A comparison on bill savings is made with the model-predictive control approach using the residential load and PV data from the Pecan Street project website under a self-consumption case.}, booktitle={2018 IEEE Power & Energy Society General Meeting (PESGM)}, publisher={IEEE}, author={Henri, Gonzague and Lu, Ning}, year={2018}, month={Aug} } @article{vanouni_lu_2018, title={A Reward Allocation Mechanism for Thermostatically Controlled Loads Participating in Intra-Hour Ancillary Services}, volume={9}, ISSN={["1949-3061"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000443200700026&KeyUID=WOS:000443200700026}, DOI={10.1109/TSG.2017.2652981}, abstractNote={When properly controlled, thermostatically controlled loads (TCLs) can shift their electricity consumption by storing heat in the thermal masses. This capability makes them proper resources to provide variety of services in power grids, specifically intrahour ancillary services. Because TCLs have diverse thermal characteristics, their capabilities of service provision can be different. Therefore, their contribution in service provision and their monetary reward might be different as well. This paper presents a reward allocation mechanism for a load serving entity to determine the payment made to TCLs according to their contribution in the provided intrahour ancillary services. A service provision capability index is proposed to quantify the TCLs capability and prioritize them accordingly. Based on the prioritization results, a reward curve is constructed to determine the TCLs payment according to their contribution to the overall provided service. The proposed rewarding system is demonstrated and verified through numerical simulations using a group of 10 000 heterogeneous heat pumps.}, number={5}, journal={IEEE TRANSACTIONS ON SMART GRID}, author={Vanouni, Maziar and Lu, Ning}, year={2018}, month={Sep}, pages={4209–4219} } @inproceedings{samaan_elizondo_vyakaranam_vallem_ke_huang_holzer_sridhar_nguyen_makarov_et al._2018, title={Combined Transmission and Distribution Test System to Study High Penetration of Distributed Solar Generation}, ISBN={9781538655832}, url={http://dx.doi.org/10.1109/tdc.2018.8440238}, DOI={10.1109/tdc.2018.8440238}, abstractNote={Transmission and distribution (T&D) standard test systems are currently defined separately, and are critical for researchers and engineers to develop and test new solutions. Growing installation of energy resources in distribution and sub-transmission systems is creating higher interactions between T&D systems. This paper proposes a standard test system to study T&D interactions for high penetration of distributed solar photovoltaic (PV) generation. The proposed test system can be used to study and propose solutions to problems such as reverse power flows from distribution to transmission and voltage control affected by PV variability. The proposed test system combines the transmission IEEE 118 bus system, with the distribution IEEE 123-node feeder. The original test systems are significantly enhanced by adding high penetration of solar PV generation with corresponding full-year 5 minute-resolution chronological data and associated power flow cases on both transmission and distribution. Conventional generation chronology is achieved by adding dispatch and unit commitment data for AC optimal power flow solutions. And chronological load data is added in both aggregated, at substation level, and disaggregated, at feeder node level, fashions. Sample applications of the data are provided highlighting voltage control challenges, and the proposed system is made available openly online [1].}, booktitle={2018 IEEE/PES Transmission and Distribution Conference and Exposition (T&D)}, publisher={IEEE}, author={Samaan, Nader and Elizondo, Marcelo A. and Vyakaranam, Bharat and Vallem, Mallikarjuna R. and Ke, Xinda and Huang, Renke and Holzer, Jesse T. and Sridhar, Siddharth and Nguyen, Quan and Makarov, Yuri V. and et al.}, year={2018}, month={Apr} } @article{ke_samaan_holzer_huang_vyakaranam_vallem_elizondo_lu_zhu_werts_et al._2018, title={Coordinative real-time sub-transmission volt–var control for reactive power regulation between transmission and distribution systems}, volume={10}, ISSN={1751-8687 1751-8695}, url={http://dx.doi.org/10.1049/iet-gtd.2018.5850}, DOI={10.1049/iet-gtd.2018.5850}, abstractNote={This study introduces a new approach for coordinating volt-var control (VVC) between sub-transmission and distribution systems through optimal reactive power dispatch of distributed energy resources (DERs) that are aggregated as virtual power plants (VPPs). At the sub-transmission level, shunt devices and the reactive power provided by the VPPs are coordinated and optimised using a VVC algorithm with weighted sum of multiple objects that include minimising voltage deviations from desirable levels at load buses, minimising loses, minimising solar curtailment, minimising demand response usage and minimising mechanical switching of shunt elements. The algorithm runs every 5 min and is solved using the AC optimal power flow technique. At the distribution level, each VPP runs a distribution VVC algorithm to dispatch reactive power from DERs. The goal of the VPP reactive power control is to meet sub-transmission service requirements while satisfying all the constraints at the distribution side. Each VPP updates its reactive power capability every 5 min to allow the sub-transmission controller to formulate the optimisation problem for the next dispatch interval. The proposed tool is simulated on a Duke Energy Carolina system to demonstrate the capability of providing voltage support by dispatching reactive power of DERs as a VPP.}, journal={IET Generation, Transmission & Distribution}, publisher={Institution of Engineering and Technology (IET)}, author={Ke, Xinda and Samaan, Nader and Holzer, Jesse and Huang, Renke and Vyakaranam, Bharat and Vallem, Mallikarjuna and Elizondo, Marcelo and Lu, Ning and Zhu, Xiangqi and Werts, Brant and et al.}, year={2018}, month={Oct} } @article{li_du_lu_2018, title={Design of a New Primary Frequency Control Market for Hosting Frequency Response Reserve Offers From Both Generators and Loads}, volume={9}, ISSN={["1949-3061"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000443200700086&KeyUID=WOS:000443200700086}, DOI={10.1109/TSG.2017.2674518}, abstractNote={This paper presents the design of a new primary frequency control (PFC) market for hosting frequency response reserve (FRR) offers from both generators and loads. Traditionally, FRR is provided by synchronous generators. Advanced control and monitoring technologies have enabled loads to provide fast and discrete PFC, which is complementary to the slow and continuous governor response provided by synchronous generators. In this paper, the performance of the PFC provided by the load is benchmarked by the equivalent amount of PFC provided by the synchronous generators at each typical system inertia condition using the actual dynamic network models and operation data of the Electric Reliability Council of Texas (ERCOT) system. Then, a new real-time PFC market mechanism is proposed to accept and value the PFC offers from both generators and loads. A few case studies are presented to illustrate the new market mechanism and demonstrate its effectiveness for mitigating price spikes. The results of this paper are applicable to other low-inertia power grids similar to the ERCOT system for procuring ancillary services that are essential to host high penetration of renewable resources.}, number={5}, journal={IEEE TRANSACTIONS ON SMART GRID}, author={Li, Weifeng and Du, Pengwei and Lu, Ning}, year={2018}, month={Sep}, pages={4883–4892} } @article{wu_he_xu_lu_lu_wang_2018, title={Hierarchical Control of Residential HVAC Units for Primary Frequency Regulation}, volume={9}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000443196400132&KeyUID=WOS:000443196400132}, DOI={10.1109/tsg.2017.2766880}, abstractNote={This paper presents a hierarchical control framework for implementing primary frequency regulation (PFR) by using residential heating, ventilating, and air-conditioning (HVAC) loads. The proposed control system consists of a load aggregator, a central controller, and a group of local controllers. The load aggregator is responsible for managing a population of HVAC loads as a virtual generator to participate in primary reserve market. The central controller dispatches the HVAC loads by assigning a triggering frequency to each HVAC load. A temperature-priority-list method is applied to avoid frequent switching on/off HVAC units when implementing PFR. The local controllers determine the ON/OFF status of HVAC units autonomously based on their triggering frequencies. A self-adjustment algorithm is proposed to correct the error in the assigned triggering frequency by considering minimum ON/OFF time of HVAC units. The proposed control framework can significantly reduce the communication needs. The simulation results indicate that by adopting the proposed control framework, one can dispatch HVAC units more efficiently at the central control level while achieve fast response at the local control level.}, number={4}, journal={Ieee Transactions on Smart Grid}, author={Wu, Xiaoyu and He, Jinghan and Xu, Yin and Lu, Jian and Lu, Ning and Wang, Xiaojun}, year={2018}, pages={3844–3856} } @inproceedings{wang_zhu_lubkeman_lu_samaan_werts_2018, title={Load Aggregation Methods for Quasi-Static Power Flow Analysis on High PV Penetration Feeders}, ISBN={9781538655832}, url={http://dx.doi.org/10.1109/tdc.2018.8440485}, DOI={10.1109/tdc.2018.8440485}, abstractNote={This paper focuses on developing load aggregation methodologies for analyzing quasi-static power flows on high photovoltaic penetrated distribution feeders so statistics of the transformer loading levels, voltage ramping events, and voltage violation events can be properly quantified. A load profile aggregation algorithm is presented to construct 24-hour, minute-by-minute load profiles at each load node on the test feeder so the aggregation of those load profiles matches the load profile measured at the feeder head. A quasi-static power flow analyses are conducted to obtain minute-by-minute power flow results that can be used to quantify transformer overloads and voltage issues in distribution systems. To demonstrate the effectiveness of the developed methodology, the IEEE-123 test feeder model and residential load profiles collected from the PECAN street project are used in the case studies. Simulation results show that the method is effective in producing the required operation statistics.}, booktitle={2018 IEEE/PES Transmission and Distribution Conference and Exposition (T&D)}, publisher={IEEE}, author={Wang, J. and Zhu, X. and Lubkeman, D. and Lu, N. and Samaan, Nader and Werts, Brant}, year={2018}, month={Apr} } @article{sun_lu_li_lubkeman_lu_2018, title={Modeling Combined Heat and Power Systems for Microgrid Applications}, volume={9}, ISSN={["1949-3061"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000443200700023&KeyUID=WOS:000443200700023}, DOI={10.1109/TSG.2017.2652723}, abstractNote={This paper presents the modeling of combined heat and power (CHP) systems for microgrid applications. When generating electricity, a CHP unit can recycle waste heat to supply building thermal loads to improve the overall efficiency of a traditional generation system. The ramping capability of a CHP unit makes it an ideal resource for load following and frequency regulation in microgrid operation. In this paper, a CHP model built in Simulink is developed. The CHP model includes three key components: generator, turbine, and absorption chiller. A new isochronous governor control strategy is proposed to provide zero-steady-state-error frequency regulation. The supply of building thermal loads is modeled to facilitate the calculation of the overall CHP system efficiency. The impact of ambient temperature on the maximum electrical output is considered. The developed model is implemented on OPAL-RT for testing the microgrid controller performance in a microgrid system.}, number={5}, journal={IEEE TRANSACTIONS ON SMART GRID}, author={Sun, Tiankui and Lu, Jian and Li, Zhimin and Lubkeman, David Lee and Lu, Ning}, year={2018}, month={Sep}, pages={4172–4180} } @inbook{zhu_henri_yan_lu_ieee_2017, title={A Cost-Benefit Study of Sizing Residential PV and ES Systems based on Synthesized Load Profiles}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000426921802031&KeyUID=WOS:000426921802031}, booktitle={2017 Ieee Power & Energy Society General Meeting}, author={Zhu, Xiangqi and Henri, Gonzague and Yan, Jiahong and Lu, Ning and Ieee}, year={2017} } @inbook{hambridge_lu_huang_yu_ieee_2017, title={A Frequency Based Real-time Electricity Rate for Residential Prosumers}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000426921800097&KeyUID=WOS:000426921800097}, booktitle={2017 Ieee Power & Energy Society General Meeting}, author={Hambridge, Sarah and Lu, Ning and Huang, Alex Q. and Yu, Ruiyang and Ieee}, year={2017} } @article{zhu_yan_lu_2017, title={A Graphical Performance-Based Energy Storage Capacity Sizing Method for High Solar Penetration Residential Feeders}, volume={8}, ISSN={["1949-3061"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000391724500001&KeyUID=WOS:000391724500001}, DOI={10.1109/tsg.2016.2577030}, abstractNote={This paper presents a graphical, performance-based energy storage capacity sizing method for residential feeders with high solar penetration levels. The rated power and storage capacity of an energy storage device (ESD) are calculated to fulfill a specified operational requirement. Three locations for installing ESDs are investigated: 1) consumer-owned ESDs inside single-family households; 2) utility-owned distribution transformer-level ESDs; and 3) third-party owned ESDs in a community. First, historical solar radiation data, residential household load data, and residential load models are used for creating the net load (load minus solar generation) ensembles at the house level with resolution of 15 min. Then, a novel graphical capacity selection method using equal probability lines on compressed, composite cumulative distribution function curves is developed for sizing the energy storage needs at the house, distribution transformer, and community levels. Demand-side management methods are investigated for further reducing the need of energy storage. Simulation results demonstrate that the proposed method avoids over- or under-sizing ESDs and allows the users to compare the marginal benefit of increasing the capacity of the ESD.}, number={1}, journal={IEEE TRANSACTIONS ON SMART GRID}, author={Zhu, Xiangqi and Yan, Jiahong and Lu, Ning}, year={2017}, month={Jan}, pages={3–12} } @inproceedings{zhu_henri_yan_lu_2017, title={A cost-benefit study of sizing residential PV and ES systems based on synthesized load profiles}, ISBN={9781538622124}, url={http://dx.doi.org/10.1109/pesgm.2017.8274305}, DOI={10.1109/pesgm.2017.8274305}, abstractNote={This paper presents a cost-benefit study of residential photovoltaic (PV) systems equipped with energy storage (ES) based on synthesized load profiles. By modeling major appliance consumptions, typical load profiles of a residential household in a given area with outdoor temperature profiles can be obtained to study whether or not installing a rooftop PV system can be profitable. Ten years' solar irradiation and temperature data in North Carolina area are used to build four case studies: a base case with no PV installation, a PV-only case, a PV with ES case, and a PV with storage and demand side management (DSM) case. Duke Energy time-of-use rate is used in major case studies, and PG&E time-of-use rate is added for comparison of bill saving brought by the PV-ES system under different rate structures. The net present value (NPV) and years of return (YR) are used to quantify the cost and benefit of installing a residential PV-ES system. Marginal savings brought by PV and ES per kW (/kWh) capacity are analyzed to help the home owners size the components of the PV-ES system.}, booktitle={2017 IEEE Power & Energy Society General Meeting}, publisher={IEEE}, author={Zhu, Xiangqi and Henri, Gonzague and Yan, Jiahong and Lu, Ning}, year={2017}, month={Jul} } @inproceedings{hambridge_lu_huang_yu_2017, title={A frequency based real-time electricity rate for residential prosumers}, DOI={10.1109/pesgm.2017.8273834}, abstractNote={The emergence of distributed generation has made a case for a deregulated, competitive, transactive energy market, operating at the level of the traditional residential consumer. These new energy players, prosumers, will interact as the larger energy generators do under the supervision of Independent System Operators (ISOs), but with their own Distributed System Operators (DSOs). This work proposes a prosumer energy management scheme, broken into a day-ahead schedule and a realtime adjustment, mirroring the ISO market structure. Within this framework, a dynamic rate can be designed and tested for the prosumer. A time-of-use (TOU) rate was combined with a frequency based, real-time dynamic rate to produce a hybrid rate that the prosumer can optimize for during its day-ahead and real-time dispatch. This hybrid rate can be calculated every one minute and applied autonomously from the grid frequency, providing secondary frequency regulation and an incentive for better solar management and use of energy storage. Such a real-time rate is the first designed for price-reactive control. In simulation, the real-time hybrid rate is compared to conventional TOU and flat rates and the final daily energy costs are calculated for a variety of residential load types with a realistic distributed solar generation curve gathered from Pecan Street Inc. Dataport. Under the one minute hybrid rate, the results indicate a near zero energy bill can be achieved for a prosumer with day-time load and smart use of energy storage.}, booktitle={2017 ieee power & energy society general meeting}, author={Hambridge, S. and Lu, N. and Huang, A. Q. and Yu, R. Y.}, year={2017} } @inproceedings{lu_lubkeman_lu_sun_li_2017, title={An An optimal microgrid dispatch algorithm for scheduling multiple CHPs in islanding operations}, DOI={10.1109/pesgm.2017.8273838}, abstractNote={A combined heat and power (CHP) unit can use its waste heat to supply building thermal loads so that the electrical heating or cooling load is reduced and the overall efficiency is improved. When multiple CHP units are running in a microgrid, it is therefore critical to balance the output of each unit so that both the electricity consumption and the building thermal loads can be satisfied with least cost. This paper presents an optimal microgrid dispatch algorithm for scheduling multiple gas-fired combined heat and power units when the microgrid is disconnected from the main grid. A coordination controller is developed to determine the power output reference for each CHP unit such that the total electric power output of all CHP units are minimized while both electric and thermal demands are met. A few test cases are presented to illustrate the effectiveness of the algorithm.}, booktitle={2017 ieee power & energy society general meeting}, author={Lu, J. and Lubkeman, David and Lu, Ning and Sun, T. K. and Li, Z. M.}, year={2017} } @inbook{lu_lubkeman_lu_sun_li_ieee_2017, title={An Optimal Microgrid Dispatch Algorithm for Scheduling Multiple CHPs in Islanding Operations}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000426921800101&KeyUID=WOS:000426921800101}, booktitle={2017 Ieee Power & Energy Society General Meeting}, author={Lu, Jian and Lubkeman, David and Lu, Ning and Sun, Tiankui and Li, Zhimin and Ieee}, year={2017} } @book{wang_zhu_lubkeman_lu_samaan_ieee_2017, title={Continuation Power Flow Analysis for PV Integration Studies at Distribution Feeders}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000417427900077&KeyUID=WOS:000417427900077}, journal={2017 Ieee Power & Energy Society Innovative Smart Grid Technologies Conference}, author={Wang, Jiyu and Zhu, Xiangqi and Lubkeman, David and Lu, Ning and Samaan, Nader and Ieee}, year={2017} } @inbook{henri_lu_carrejo_ieee_2017, title={Design of a Novel Mode-based Energy Storage Controller for Residential PV Systems}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000428016500167&KeyUID=WOS:000428016500167}, booktitle={2017 Ieee Pes Innovative Smart Grid Technologies Conference Europe}, author={Henri, Gonzague and Lu, Ning and Carrejo, Carlos and Ieee}, year={2017} } @inproceedings{henri_lu_carrejo_2017, title={Design of a novel mode-based energy storage controller for residential PV systems}, DOI={10.1109/isgteurope.2017.8260258}, abstractNote={This paper presents a novel mode-based controller design approach to control energy storage devices (ESDs) for residential PV applications. Different from the traditional controller design approach, the mode-based approach assumes that an ESD is equipped with a set of predetermined real-time control modes. Thus, the control objective becomes choosing the best operation mode of the ESD to achieve the best performance at the lowest cost instead of the charging and discharging power levels. As a result, a two-stage algorithm is developed. In the first stage, an economic model predictive control (EMPC) algorithm is used to determine the optimal charging or discharging power. In the second stage, based on the EMPC result, the controller eliminates unsuitable modes and selects the best operation modes among the suitable modes. Residential electricity consumption data collected in the PECAN Street Project are used for testing and validation of the proposed algorithms. Simulation results show that the performance of the mode-based controller is robust and consistent across different residential load patterns.}, booktitle={2017 ieee pes innovative smart grid technologies conference europe (isgt-europe)}, author={Henri, G. and Lu, N. and Carrejo, C.}, year={2017} } @book{lu_2017, place={Raleigh, NC}, title={Distribution Planning Criteria and Tools for Future Distributed Energy Resource Penetration Scenarios using Probabilistic Approaches}, institution={North Carolina State University and Clemson University}, author={Lu, N.}, year={2017} } @article{chen_wei_sun_lu_sun_zhu_2017, title={Multi-area distributed three-phase state estimation for unbalanced active distribution networks}, volume={5}, ISSN={["2196-5420"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000410794000010&KeyUID=WOS:000410794000010}, DOI={10.1007/s40565-016-0237-0}, abstractNote={This paper proposes a new multi-area framework for unbalanced active distribution network (ADN) state estimation. Firstly, an innovative three-phase distributed generator (DG) model is presented to take the asymmetric characteristics of DG three-phase outputs into consideration. Then a feasible method to set pseudo -measurements for unmonitored DGs is introduced. The states of DGs, together with the states of alternating current (AC) buses in ADNs, were estimated by using the weighted least squares (WLS) method. After that, the ADN was divided into several independent subareas. Based on the augmented Lagrangian method, this work proposes a fully distributed three-phase state estimator for the multi-area ADN. Finally, from the simulation results on the modified IEEE 123-bus system, the effectiveness and applicability of the proposed methodology have been investigated and discussed.}, number={5}, journal={JOURNAL OF MODERN POWER SYSTEMS AND CLEAN ENERGY}, author={Chen, Sheng and Wei, Zhinong and Sun, Guoqiang and Lu, Ning and Sun, Yonghui and Zhu, Ying}, year={2017}, month={Sep}, pages={767–776} } @inbook{zhu_wang_mulcahy_lubkeman_lu_samaan_huang_ieee_2017, title={Voltage-Load Sensitivity Matrix Based Demand Response for Voltage Control in High Solar Penetration Distribution Feeders}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000426921800145&KeyUID=WOS:000426921800145}, booktitle={2017 Ieee Power & Energy Society General Meeting}, author={Zhu, Xiangqi and Wang, Jiyu and Mulcahy, David and Lubkeman, David L. and Lu, Ning and Samaan, Nader and Huang, Renke and Ieee}, year={2017} } @inproceedings{zhu_wang_mulcahy_lubkeman_lu_samaan_huang_2017, title={Voltage-load sensitivity matrix based demand response for voltage control in high solar penetration distribution feeders}, ISBN={9781538622124}, url={http://dx.doi.org/10.1109/pesgm.2017.8273887}, DOI={10.1109/pesgm.2017.8273887}, abstractNote={This paper presents a voltage-load sensitivity matrix (VLSM) based voltage control method to deploy demand response resources for controlling voltage in high solar penetration distribution feeders. The IEEE 123-bus system in OpenDSS is used for testing the performance of the preliminary VLSM-based voltage control approach. A load disaggregation process is applied to disaggregate the total load profile at the feeder head to each load nodes along the feeder so that loads are modeled at residential house level. Measured solar generation profiles are used in the simulation to model the impact of solar power on distribution feeder voltage profiles. Different case studies involving various PV penetration levels and installation locations have been performed. Simulation results show that the VLSM algorithm performance meets the voltage control requirements and is an effective voltage control strategy.}, booktitle={2017 IEEE Power & Energy Society General Meeting}, publisher={IEEE}, author={Zhu, Xiangqi and Wang, Jiyu and Mulcahy, David and Lubkeman, David L. and Lu, Ning and Samaan, Nader and Huang, Renke}, year={2017}, month={Jul} } @inbook{zhu_yan_dong_lu_ieee_2016, title={A Matlab-Based Home Energy Management Algorithm Development Toolbox}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000399937903178&KeyUID=WOS:000399937903178}, booktitle={2016 Ieee Power and Energy Society General Meeting}, author={Zhu, Xiangqi and Yan, Jiahong and Dong, Lining and Lu, Ning and Ieee}, year={2016} } @article{jiang_mu_jia_lu_yuan_yan_li_2016, title={A Novel Dominant Mode Estimation Method for Analyzing Inter-Area Oscillation in China Southern Power Grid}, volume={7}, ISSN={["1949-3061"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000391722100038&KeyUID=WOS:000391722100038}, DOI={10.1109/tsg.2016.2533621}, abstractNote={This paper proposes a new approach to estimate dominant mode for monitoring inter-area oscillation in the China Southern power grid (CSG) by the use of phasor measurement units (PMUs) under both ringdown and ambient conditions. The state space model is identified by the data driven stochastic subspace identification (Data-SSI) algorithm. The canonical variate algorithm is used first to construct the weighted projection matrix of the Data-SSI. Then, the criterion for model order selection is developed to estimate the model order, and the linear model of power system is built with Data-SSI. The dominant oscillation modes are calculated by eigenvalue analysis. To accurately identify the dominant modes, repetitive results are calculated with model order variation, and then clustering analysis and stepwise refinement are applied to discriminating the dominant modes from trivial ones to improve the estimation accuracy. Field-measurement data collected by PMUs in CSG is used to validate the proposed algorithm. The comparison between existing mode estimation techniques and the proposed approach demonstrates its accuracy and robustness under both ringdown and ambient conditions.}, number={5}, journal={IEEE TRANSACTIONS ON SMART GRID}, author={Jiang, Tao and Mu, Yunfei and Jia, Hongjie and Lu, Ning and Yuan, Haoyu and Yan, Jiahong and Li, Weifeng}, year={2016}, month={Sep}, pages={2549–2560} } @inbook{sun_li_lu_lu_ieee_2016, title={A Preliminary Study on the Thevenin Equivalent Parameters of DFIG Wind Farms}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000399937901075&KeyUID=WOS:000399937901075}, booktitle={2016 Ieee Power and Energy Society General Meeting}, author={Sun, Tiankui and Li, Zhimin and Lu, Jian and Lu, Ning and Ieee}, year={2016} } @book{zhu_yan_lu_ieee_2016, title={A Probabilistic-based PV and Energy Storage Sizing Tool for Residential Loads}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000386922500087&KeyUID=WOS:000386922500087}, journal={2016 Ieee/Pes Transmission and Distribution Conference and Exposition}, author={Zhu, Xiangqi and Yan, Jiahong and Lu, Ning and Ieee}, year={2016} } @inbook{wu_he_yip_lu_lu_ieee_2016, title={A Two-Stage Random Forest Method for Short-term Load Forecasting}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000399937900226&KeyUID=WOS:000399937900226}, booktitle={2016 Ieee Power and Energy Society General Meeting}, author={Wu, Xiaoyu and He, Jinghan and Yip, Tony and Lu, Jian and Lu, Ning and Ieee}, year={2016} } @inproceedings{zhu_yan_dong_lu_2016, title={A matlab-based home energy management algorithm development toolbox}, DOI={10.1109/pesgm.2016.7742017}, abstractNote={This paper presents the architecture and modeling approach of a Matlab-based toolbox for developing and testing home energy management (HEM) algorithms under a number of typical operation conditions. This toolbox serves as a developer platform that includes a graphical user interface, a model database, a computational engine, and an input-output database. The model database consists of home appliance models, energy storage models, baseload models, roof-top photovoltaic models, as well as typical weather profiles. The graphical interface allows the users to select different inputs such as utility rate structure, customer comfort settings, solar profiles, and outdoor temperature profiles. The HEM algorithms serve as the computational engines to power the virtual house so that the performance of those algorithms can be evaluated fairly using the same set of inputs and models. Simulation results have demonstrated the effectiveness of the modeling platform when developing HEM algorithms.}, booktitle={2016 ieee power and energy society general meeting (pesgm)}, author={Zhu, X. Q. and Yan, J. H. and Dong, L. N. and Lu, N.}, year={2016} } @inproceedings{sun_li_lu_lu_2016, title={A preliminary study on the Thevenin equivalent parameters of DFIG wind farms}, DOI={10.1109/pesgm.2016.7741429}, abstractNote={It is an important but challenging issue to represent a wind farm using an equivalent model. This paper tries to develop an equivalent representation of a wind farm for power system planning and operation studies using Thevenin equivalent circuit. In the paper, a series string configuration of wind farms with doubly-fed induction generator (DFIG) wind turbines is emphasized, and case studies have been conducted to investigate the characteristics of the equivalent parameters of such a wind farm under different control strategies and wind speeds. Simulation results show that the equivalent parameters are strongly related to the wind speed, particularly when the constant power factor control strategy is employed for wind turbines. It can also be concluded that, compared to the constant power factor case, the constant voltage control scheme possesses better performance and thus is more popular for power system operation and control.}, booktitle={2016 ieee power and energy society general meeting (pesgm)}, author={Sun, T. K. and Li, Z. M. and Lu, J. and Lu, N.}, year={2016} } @inproceedings{zhu_yan_lu_2016, title={A probabilistic-based PV and energy storage sizing tool for residential loads}, DOI={10.1109/tdc.2016.7519940}, abstractNote={This paper presents a probabilistic-based sizing tool for residential home owners, load serving entities, and utilities to select energy storage (ES) and photovoltaic (PV) based on historical load characteristics and load management options. The inputs of the tool include historical residential load profiles and solar radiation data. The outputs of the tool include ensembles of the net load profiles (load minus solar), with and without applying load energy management for different PV and ES installation capacities. The operation statistics of the ES is used to determine the confidence levels of meeting selected performance criterion. In the simulation, a set of 1-year, 15-minute data collected from 50 actual residential homes is used as the load inputs. A set of 1-year, 5-minute actual solar radiation data is used as the solar inputs. Managing load consumptions for reducing the size of ES is investigated by controlling air conditioning loads. Simulation results show that the probabilistic-based sizing method can give the users a clear comparison of the tradeoffs among different options and assist them make more informed decisions.}, booktitle={2016 IEEE/PES Transmission and Distribution Conference and Exposition (T&D)}, author={Zhu, X. Q. and Yan, J. H. and Lu, N.}, year={2016} } @inproceedings{wu_he_yip_lu_lu_2016, title={A two-stage random forest method for short-term load forecasting}, DOI={10.1109/pesgm.2016.7741295}, abstractNote={Machine learning methods are the main stream algorithms applied in short term load forecasting. However, typical machine learning methods consisting of Artificial Neural Network (ANN) and Support Vector Regression (SVR) have deficiencies hard to overcome, such as easy to be trapped in local optimization (for ANN) or hard to decide kernel parameter and penalty parameter (for SVR). On the other hand, grey relational analysis is an effective method to select proper historical data as training set for training machine learning models. But it is not comprehensive and accurate enough. In this paper, a new two-stage hybrid algorithm aimed to solve these two problems is proposed. Random Forest (RF) method is introduced as the machine learning method, which will not cause overfitting problem and parameters are easy to be tuned. Furthermore, Grey Relational Projection (GRP) is introduced to select similar historical data to train random forest models. The final forecasting results based on real load data prove this new two-stage method performs better than the other two common methods.}, booktitle={2016 ieee power and energy society general meeting (pesgm)}, author={Wu, X. Y. and He, J. H. and Yip, T. and Lu, J. and Lu, N.}, year={2016} } @article{wang_zhou_jia_wang_lu_sui_fan_2016, title={An energy-constrained state priority list model using deferrable electrolyzers as a load management mechanism}, volume={167}, ISSN={["1872-9118"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000373748400016&KeyUID=WOS:000373748400016}, DOI={10.1016/j.apenergy.2015.10.129}, abstractNote={To reduce the consumption of fossil fuel and greenhouse gas (GHG) emissions, incentive-based policies are used to encourage end-users to utilize more clean energy. Hydrogen energy is an ideal clean energy that can be integrated into the next generation power grid. Deferrable electrolyzers (DEs), as a typical electricity-to-hydrogen conversion devices and capable of modulating power consumption, can convert excessive power to store electricity as hydrogen. Therefore it can be used as a method for load management. The main contribution of this paper is to propose an energy-constrained state priority list (ECSPL) model, for analyzing the charging response of aggregated loads consisting of DE units. The typical hysteresis control of DEs as a load management mechanism is first discussed. A characteristic parameter, i.e. the energy state of DE charging load, is used to group and prioritize the DE units. The proposed ECSPL model optimally determines the operating status of DE charging and standby process, and it maintains the user-desired DE charging trajectory considering customer-constraints. The proposed model maintains the diversity of operating status of DE charging and standby process to prevent unexpected synchronization phenomenon for operating status. To evaluate the performance of the proposed method, an estimated baseline of the aggregated DE charging loads is obtained based on natural hysteresis control. The ECSPL control method of DE units for intra-hour load balancing is then evaluated. The effects of different energy-constraints, deadbands of sampled end-use state comparison, error associated with the charging-trajectory measurements are modeled to evaluate the performance of controlled DE group. The ECSPL model is described and demonstrated by the modeling results of investigated DE units.}, journal={APPLIED ENERGY}, author={Wang, Dan and Zhou, Yue and Jia, Hongjie and Wang, Chengshan and Lu, Ning and Sui, Pang-Chieh and Fan, Menghua}, year={2016}, month={Apr}, pages={201–210} } @article{hong_chen_huang_lu_xie_zareipour_2016, title={Big Data Analytics for Grid Modernization}, volume={7}, ISSN={["1949-3061"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000391722100022&KeyUID=WOS:000391722100022}, DOI={10.1109/tsg.2016.2593358}, abstractNote={Advanced analytics plays a vital role in the era of big data, such as managing smart cities, predicting crime activities, optimizing medicine formula based on genetic defects, detecting financial frauds, and personalizing marketing campaigns. Information extracted from the big data benefits many industries in their day-to-day operations. The deployment of phasor measurement units (PMUs), smart meters and other smart devices has offered engineers the access to a large variety of data at an unprecedented granularity and volume. However, the old data management systems and applications are not designed to handle the big data. Therefore, how to extract actionable information and values out of the big data and how to integrate the information into grid operations and planning to ensure the secure, reliable and economical supply of electricity are becoming increasingly critical.}, number={5}, journal={IEEE TRANSACTIONS ON SMART GRID}, author={Hong, Tao and Chen, Chen and Huang, Jianwei and Lu, Ning and Xie, Le and Zareipour, Hamidreza}, year={2016}, month={Sep}, pages={2395–2396} } @inbook{li_lubkeman_lu_zhu_ieee_2016, title={Control Strategies for Residential Microgrids during Islanded Situation}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000399937901035&KeyUID=WOS:000399937901035}, booktitle={2016 Ieee Power and Energy Society General Meeting}, author={Li, Qinmiao and Lubkeman, David L. and Lu, Ning and Zhu, Xiangqi and Ieee}, year={2016} } @inproceedings{li_lubkeman_lu_zhu_2016, title={Control strategies for residential microgrids during islanded situation}, DOI={10.1109/pesgm.2016.7741387}, abstractNote={Microgrids can serve to integrate distributed energy resources (DERs) and controllable loads in a smarter and more reliable fashion. The operation of residential microgrids with DER during islanded situation is of great significance to both customers and utility providers. This paper proposes two control strategies for a residential microgrid that has a shared energy storage (ES) in islanded mode. With ES being the only energy resource, these strategies rationally allocate energy over the islanded time period and also regulate loads to coordinate with ES. A simulation testbed based on household load models for typical residential devices is utilized. Test cases for islanded-situation days using these control strategies are simulated for validation. Finally, simulation results of control signals and resulting load profiles are shown and analyzed. These two control strategies are proved to be effective for the energy management of a residential microgrid during islanded situation.}, booktitle={2016 ieee power and energy society general meeting (pesgm)}, author={Li, Q. M. and Lubkeman, David and Lu, Ning and Zhu, X. Q.}, year={2016} } @inbook{ke_jiang_lu_ieee_2016, title={Load Profile Analysis and Short-term Building Load Forecast for a University Campus}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000399937903195&KeyUID=WOS:000399937903195}, booktitle={2016 Ieee Power and Energy Society General Meeting}, author={Ke, Xinda and Jiang, Anjie and Lu, Ning and Ieee}, year={2016} } @inproceedings{ke_jiang_lu_2016, title={Load profile analysis and short-term building load forecast for a university campus}, DOI={10.1109/pesgm.2016.7742034}, abstractNote={Nowadays, advanced metering infrastructure allows us to record building energy consumption at much higher resolutions. This paper presents the methods for building load profile analysis and forecast using the 15-minute data collected at a substation feeder at the Centennial Campus of North Carolina State University from May 2012 to April 2014. Building load signatures for benchmarking building load consumptions are first analyzed and extracted from load related environmental factors such as time of the day, temperature and humidity, etc. Then, methods to forecast hours-ahead building energy consumptions are developed. Comparisons are made to derive the benefit of having high resolution environmental data sets.}, booktitle={2016 ieee power and energy society general meeting (pesgm)}, author={Ke, X. D. and Jiang, A. J. and Lu, N.}, year={2016} } @article{du_hui_lu_2016, title={Procurement of regulation services for a grid with high-penetration wind generation resources: a case study of ERCOT}, volume={10}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000390096500013&KeyUID=WOS:000390096500013}, DOI={10.1049/iet-gtd.2016.0451}, abstractNote={This study presents two enhancements at the Electric Reliability Council of Texas (ERCOT) for coping with the uncertainties and variations brought by high penetration of wind generation resources (GRs). The first enhancement is the incorporation of a novel short-term wind forecast algorithm into the look-ahead dispatch process to improve the calculation of locational marginal prices and generation schedules. The second enhancement is the development of a multi-time-scale method for quantifying regulation service requirements considering the combined impact of wind variations on governor response, automatic generation control, and economic dispatch results. A simulation model that is capable of simulating all relevant scheduling and operation processes from a few seconds to a few hours is developed to verify the performance of the proposed method. The ERCOT operational model and historical data are used to demonstrate that the derived regulation requirements can meet the ERCOT reliability needs by considering additional generation variations and uncertainties caused by wind GRs. The proposed methods are readily applicable to other regional power grids with high penetration of variable GRs.}, number={16}, journal={Iet Generation Transmission & Distribution}, author={Du, Pengwei and Hui, Hailong and Lu, Ning}, year={2016}, pages={4085–4093} } @inbook{hambridge_huang_lu_ieee_2016, title={Proposing a Frequency Based Real-Time Energy Market and Economic Dispatch Strategy}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000399937900250&KeyUID=WOS:000399937900250}, booktitle={2016 Ieee Power and Energy Society General Meeting}, author={Hambridge, Sarah and Huang, Alex Q. and Lu, Ning and Ieee}, year={2016} } @inproceedings{hambridge_huang_lu_2016, title={Proposing a frequency based real-time energy market and economic dispatch strategy}, DOI={10.1109/pesgm.2016.7741320}, abstractNote={Smart grid technology and the Energy Internet are reliant on a new, competitive, deregulated energy market, that supports energy transactions among energy players: utilities, consumers, and prosumers, alike. Such an energy market is being developed to ensure grid reliability, health, and economic operation with the emergence of microgrids, distributed renewable generation, Distributed Energy Storage Devices (DESDs), controllable loads, and Energy Cells. The solid-state transformer (SST) presents a new opportunity to regulate power flow from Energy Cells to the grid in real-time. As the proposed Energy Router of the smart grid, the SST will facilitate energy transactions as an intelligent node, providing communication, frequency and power management. In this work, a frequency based real-time energy market is proposed. Here, it is demonstrated that the grid frequency is a real-time price signal (measured by the SST) which can be used to autonomously calculate the real-time energy price for all energy players, reducing the need to establish complicated networks to determine the market clearing price. In addition to providing a real-time price, frequency based pricing increases grid reliability as energy players respond to frequency deviations and provide frequency regulation as an ancillary service. A simulation was designed to respond to the steady-state frequency deviation in five minute intervals. A pricing curve and DESD response curve were designed to identify key parameters and solve for optimal solutions that benefit energy producers and consumers.}, booktitle={2016 ieee power and energy society general meeting (pesgm)}, author={Hambridge, S. and Huang, A. Q. and Lu, N.}, year={2016} } @article{ke_wu_rice_kintner-meyer_lu_2016, title={Quantifying impacts of heat waves on power grid operation}, volume={183}, ISSN={["1872-9118"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000391897600041&KeyUID=WOS:000391897600041}, DOI={10.1016/j.apenergy.2016.08.188}, abstractNote={Climate change is projected to cause an increase in the severity and frequency of extreme weather events such as heat waves and droughts. Such changes present planning and operating challenges and risks to many economic sectors. In the electricity sector, statistics of extreme events in the past have been used to help plan for future peak loads, determine associated infrastructure requirements, and evaluate operational risks, but industry-standard planning tools have yet to be coupled with or informed by temperature models to explore the impacts of the “new normal” on planning studies. For example, high ambient temperatures during heat waves reduce the output capacity and efficiency of gas-fired combustion turbines just when they are needed most to meet peak demands. This paper describes the development and application of a production cost and unit commitment model coupled to high resolution, hourly temperature data and a temperature-dependent load model. The coupled system has the ability to represent the impacts of hourly temperature on load conditions and available capacity and efficiency of combustion turbines, and therefore capture the potential impacts on system reserve and production cost. Ongoing work expands this capability to address the impacts of water availability and temperature on power grid operation.}, journal={APPLIED ENERGY}, author={Ke, Xinda and Wu, Di and Rice, Jennie and Kintner-Meyer, Michael and Lu, Ning}, year={2016}, month={Dec}, pages={504–512} } @inbook{lu_lu_wu_he_ieee_2016, title={Short-term HVAC Load Forecasting Algorithms for Home Energy Management}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000399937900279&KeyUID=WOS:000399937900279}, booktitle={2016 Ieee Power and Energy Society General Meeting}, author={Lu, Jian and Lu, Ning and Wu, Xiaoyu and He, Jinghan and Ieee}, year={2016} } @inproceedings{lu_lu_wu_he_2016, title={Short-term HVAC load forecasting algorithms for home energy management}, DOI={10.1109/pesgm.2016.7741349}, abstractNote={This paper presents the forecasting algorithms for determining the electricity usage and operation status of residential heating, ventilating, and air conditioning (HVAC) systems. Two algorithms are presented based on what types of measured data can be received by the home energy management system (HEMS). Algorithm 1 is developed assuming only HVAC status is available to forecast the future HVAC usage. Algorithm 2 is developed for cases that the HVAC operation status, room temperature and outdoor temperature time series are known. The sensitivity of the room temperature change rate to outdoor temperature is derived and used to forecast the HVAC operation status. Results show that Algorithm 1 performs well for very short term forecast (less than 1 hour) and Algorithm 2 outperforms Algorithm 1 when forecasting HVAC behaviors for longer periods (from one hour to several hours) under a broader operation conditions such as continuously running or cold start. Both algorithms are measurement-based and require little computational resources and time to implement so that they fit well for providing HVAC status estimation to the HEM system for scheduling HVAC loads.}, booktitle={2016 ieee power and energy society general meeting (pesgm)}, author={Lu, J. and Lu, N. and Wu, X. Y. and He, J. H.}, year={2016} } @inbook{chen_wei_sun_sun_lu_ieee_2016, title={Steady-state Security Regions of Electricity-gas Integrated Energy Systems}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000399937901117&KeyUID=WOS:000399937901117}, booktitle={2016 Ieee Power and Energy Society General Meeting}, author={Chen, Sheng and Wei, Zhinong and Sun, Guoqiang and Sun, Yonghui and Lu, Ning and Ieee}, year={2016} } @inproceedings{chen_wei_sun_sun_lu_2016, title={Steady-state security regions of electricity-gas integrated energy systems}, DOI={10.1109/pesgm.2016.7741474}, abstractNote={The integrated energy systems (IESs), composed of deeply interdependent electric power systems (EPSs) and natural-gas systems (NGSs), are expected to play an important role in the transition to low-carbon sustainable energy systems. To facilitate the security assessment of IESs, this paper initially proposes the concept of IES security region. First, The security region of the IES is defined as a set of energy flow injections for which the energy flow equations and security constraints are satisfied. Next, a set of critical points on the boundary of security region is derived from repeated energy flow solutions. After that, based on the critical points, the hyperplane approximation method is employed to obtain the critical boundaries and further determine the security region. Finally, the effectiveness of the proposed methodology has been verified.}, booktitle={2016 ieee power and energy society general meeting (pesgm)}, author={Chen, S. and Wei, Z. N. and Sun, G. Q. and Sun, Y. H. and Lu, N.}, year={2016} } @inbook{yan_zheng_lu_ieee_2016, title={Temperature-Load Sensitivity Study for Adjusting MISO Day-ahead Load Forecast}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000399937901186&KeyUID=WOS:000399937901186}, booktitle={2016 Ieee Power and Energy Society General Meeting}, author={Yan, Jiahong and Zheng, Hui and Lu, Ning and Ieee}, year={2016} } @inproceedings{yan_zheng_lu_2016, title={Temperature-load sensitivity study for adjusting miso day-ahead load forecast}, DOI={10.1109/pesgm.2016.7741548}, abstractNote={This paper presents the results of a temperature-load sensitivity study carried out at the Midcontinent Independent System Operator (MISO) for adjusting MISO day-ahead load forecast. As the area operated by MISO is growing rapidly, operators at MISO have to examine the day-ahead load forecast results generated by commercial software packages on a daily basis and manually correct anticipated discrepancies to enhance the forecast accuracy. To quantify the adjustment of the forecasted load, a series of temperature-load sensitivity studies are conducted using the actual MISO load data from past 5 years. A piecewise general linear model (GLM) is developed to capture the impact of time-dependent factors and temperature variations on the magnitude of MISO temperature-load sensitivity. A numerical study case compares the results before and after the tuning with the presented temperature-load sensitivity analysis.}, booktitle={2016 ieee power and energy society general meeting (pesgm)}, author={Yan, J. H. and Zheng, H. and Lu, N.}, year={2016} } @inbook{ke_lu_wu_kintner-meyer_ieee_2015, title={A Modified Priority List-Based MILP Method for Solving Large-Scale Unit Commitment Problems}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000371397504036&KeyUID=WOS:000371397504036}, booktitle={2015 Ieee Power & Energy Society General Meeting}, author={Ke, Xinda and Lu, Ning and Wu, Di and Kintner-Meyer, Michael and Ieee}, year={2015} } @inproceedings{ke_lu_wu_kintner-meyer_2015, title={A modified priority list-based MILP method for solving large-scale unit commitment problems}, DOI={10.1109/pesgm.2015.7286561}, abstractNote={This paper presents a two-step modified priority list (MPL) based mixed integer linear programming (MILP) method for improving the computational speed of unit commitment (UC) programs while preserving optimality. In the first step, the heuristics of UC results for a given generation fleet are investigated to develop the MPL. A subset of the generators are determined to be online (committed) or offline (uncommitted) within a planning period (e.g., a week), based on the demand curve and generator priority list. Then, for generators whose on/off status is predetermined, the corresponding binary variables are removed from the MILP solving process. After this simplification, the remaining problem can be solved much faster using an off-the-shelf MILP solver, based on the branch-and-bound algorithm. Scale factors are used to adjust the tradeoff between solution speed and level of optimality. Simulation results show that the proposed method can significantly speed up the large-scale UC problem with negligible compromise in optimality by selecting appropriate scale factors.}, booktitle={2015 ieee power & energy society general meeting}, author={Ke, X. D. and Lu, N. and Wu, D. and Kintner-Meyer, M.}, year={2015} } @article{zhan_hu_song_lu_xu_jia_2015, title={A probability transition matrix based decentralized electric vehicle charging method for load valley filling}, volume={125}, ISSN={["1873-2046"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000358101200001&KeyUID=WOS:000358101200001}, DOI={10.1016/j.epsr.2015.03.013}, abstractNote={This paper presents a decentralized control method to schedule EV (electric vehicle) charging loads to fill the overnight load valley while meeting customers’ charging requirements. A PTM (probability transition matrix) is calculated at the aggregator side as the control signal to guide EV charging processes based on submitted EV charging schedules. Elements of the PTM represent the transition probabilities of moving a charging load from one time period to another. At the EV side, each EV individually updates its charging schedule according to its charging requirements and the PTM. Then the updated schedules are sent back to the aggregator. This process is repeated iteratively until convergence. In this method, no optimal control problems need to be solved locally so that its implementation on the EV side requires low computation capability. Simulation results show that the proposed method can create desired EV charging schedules for load valley filling within only several iterations, making it suitable for real-time implementation.}, journal={ELECTRIC POWER SYSTEMS RESEARCH}, author={Zhan, Kaiqiao and Hu, Zechun and Song, Yonghua and Lu, Ning and Xu, Zhiwei and Jia, Long}, year={2015}, month={Aug}, pages={1–7} } @article{ke_lu_jin_2015, title={Control and Size Energy Storage Systems for Managing Energy Imbalance of Variable Generation Resources}, volume={6}, ISSN={["1949-3029"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000346733200008&KeyUID=WOS:000346733200008}, DOI={10.1109/tste.2014.2355829}, abstractNote={This paper presents control algorithms and sizing strategies for using energy storage to manage energy imbalance for variable generation resources. The control objective is to minimize the hourly generation imbalance between the actual and the scheduled generation of wind farms. Three control algorithms are compared: 1)tracking minute-by-minute power imbalance; 2)postcompensation; and 3)precompensation. Measured data from a wind farm are used in the study. The results show that tracking minute-by-minute power imbalance achieves the best performance by keeping hourly energy imbalance zero. However, the energy storage system (ESS) will be significantly oversized. Postcompensation reduces the power rating of the ESS but the hourly energy imbalance may not be reduced to zero when a large and long-lasting power imbalance occurs. A linear regression forecasting algorithm is developed for a two-stage precompensation algorithm to precharge or predischarge the ESS based on the predicted energy imbalance. An equivalent charge cycle estimation method is proposed to evaluate the effect of providing the energy balancing service on battery life. The performance comparison shows that the precompensation method reduces the size of the ESS by 30% with satisfactory performance.}, number={1}, journal={IEEE TRANSACTIONS ON SUSTAINABLE ENERGY}, author={Ke, Xinda and Lu, Ning and Jin, Chunlian}, year={2015}, month={Jan}, pages={70–78} } @inbook{ke_lu_jin_ieee_2015, title={Control and Size Energy Storage Systems for Managing Energy Imbalance of Variable Generation Resources}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000371397504079&KeyUID=WOS:000371397504079}, booktitle={2015 Ieee Power & Energy Society General Meeting}, author={Ke, Xinda and Lu, Ning and Jin, Chunlian and Ieee}, year={2015} } @inproceedings{ke_lu_jin_2015, title={Control and size energy storage systems for managing energy imbalance of variable generation resources}, DOI={10.1109/pesgm.2015.7286609}, abstractNote={Summary form only given: This paper presents control algorithms and sizing strategies for using energy storage to manage energy imbalance for variable generation resources. The control objective is to minimize the hourly generation imbalance between the actual and the scheduled generation of wind farms. Three control algorithms are compared: (1) tracking minute-by-minute power imbalance; (2) postcompensation; and (3) precompensation. Measured data from a wind farm are used in the study. The results show that tracking minute-by-minute power imbalance achieves the best performance by keeping hourly energy imbalance zero. However, the energy storage system (ESS) will be significantly oversized. Postcompensation reduces the power rating of the ESS but the hourly energy imbalance may not be reduced to zero when a large and long-lasting power imbalance occurs. A linear regression forecasting algorithm is developed for a two-stage precompensation algorithm to precharge or predischarge the ESS based on the predicted energy imbalance. An equivalent charge cycle estimation method is proposed to evaluate the effect of providing the energy balancing service on battery life. The performance comparison shows that the precompensation method reduces the size of the ESS by 30% with satisfactory performance.}, booktitle={2015 ieee power & energy society general meeting}, author={Ke, X. D. and Lu, N. and Jin, C. L.}, year={2015} } @article{wai_beaudin_zareipour_schellenberg_lu_2015, title={Cooling Devices in Demand Response: A Comparison of Control Methods}, volume={6}, ISSN={["1949-3061"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000346731400025&KeyUID=WOS:000346731400025}, DOI={10.1109/tsg.2014.2358579}, abstractNote={Demand response plays an important role in the development of the smart grid, which can effectively manage society's energy consumption. Cooling devices, such as refrigerators and freezers, are ideal devices for demand-response programs because their energy states can be controlled without reducing the lifestyle and comfort of the residents. Conversely, managing air conditioning and space heating would affect a resident's comfort level. Direct compressor control and thermostat control methods have been proposed in the past for controlling cooling devices but they are never studied concurrently. This paper proposes a new control mechanism and compares the effectiveness of the three control mechanisms for cooling devices in demand response. In addition, this paper illustrates the need for a damping strategy to mitigate demand oscillations that occur from synchronous fleet control.}, number={1}, journal={IEEE TRANSACTIONS ON SMART GRID}, author={Wai, Chon Hou and Beaudin, Marc and Zareipour, Hamidreza and Schellenberg, Antony and Lu, Ning}, year={2015}, month={Jan}, pages={249–260} } @article{vanouni_lu_2015, title={Improving the Centralized Control of Thermostatically Controlled Appliances by Obtaining the Right Information}, volume={6}, ISSN={["1949-3061"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000350338100048&KeyUID=WOS:000350338100048}, DOI={10.1109/tsg.2014.2357211}, abstractNote={This letter presents a performance enhancement for a previously developed direct load control scheme that controls (toggles on/off) thermostatically controlled appliances (TCAs) through two-way communication infrastructure for providing load balancing services. In addition to device operating temperature and on/off status (TCA states), two more pieces of information, rates of temperature increase and decrease (RTI/RTD), are calculated at each TCA and communicated to the central controller. By communicating the RTI/RTD to the central controller, the same or even better control performance can be achieved at 2-3 times longer sampling periods, showing significant reduction of the communication needs from each TCA to the central controller.}, number={2}, journal={IEEE TRANSACTIONS ON SMART GRID}, author={Vanouni, Maziar and Lu, Ning}, year={2015}, month={Mar}, pages={946–948} } @article{dan_yue_hongjie_chengshan_ning_menghua_2015, title={Probabilistic total transfer capability analysis based on static voltage stability region integrated with a modified distributed-level nodal-loading model}, volume={58}, ISSN={["1869-1900"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000367028400009&KeyUID=WOS:000367028400009}, DOI={10.1007/s11431-015-5964-3}, number={12}, journal={SCIENCE CHINA-TECHNOLOGICAL SCIENCES}, author={Dan, Wang and Yue, Zhou and HongJie, Jia and ChengShan, Wang and Ning, Lu and MengHua, Fan}, year={2015}, month={Dec}, pages={2072–2084} } @article{du_li_ke_lu_ciniglio_colburn_anderson_2015, title={Probabilistic-Based Available Transfer Capability Assessment Considering Existing and Future Wind Generation Resources}, volume={6}, ISSN={["1949-3029"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000361680800010&KeyUID=WOS:000361680800010}, DOI={10.1109/tste.2015.2425354}, abstractNote={This paper presents a probabilistic-based approach for available transfer capability (ATC) assessment. A composite algorithm is developed to generate ensembles of future wind generation scenarios for the existing and planned wind sites using both measured and model-produced wind data. Then, the ensembles of wind and load are used to calculate their respective probability density functions (pdfs), which are subsequently used to calculate the probabilistic-based ATC for a selected transmission corridor. The method has been tested and validated using historical and operational data provided by the Idaho Power Co. The results show that the method can effectively quantify the uncertainties in the ATC assessment introduced by variable generation resources and load variations. As a result, the grid planners will inform the likelihood for the transmission corridor to exceed its transfer capacity in any targeted future years as well as the duration of such events.}, number={4}, journal={IEEE TRANSACTIONS ON SUSTAINABLE ENERGY}, author={Du, Pengwei and Li, Weifeng and Ke, Xinda and Lu, Ning and Ciniglio, Orlando A. and Colburn, Mitchel and Anderson, Phillip M.}, year={2015}, month={Oct}, pages={1263–1271} } @inbook{yan_zhu_lu_ieee_2015, title={Smart Hybrid House Test Systems in a Solid-state Transformer Supplied Microgrid}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000371397504026&KeyUID=WOS:000371397504026}, booktitle={2015 Ieee Power & Energy Society General Meeting}, author={Yan, Jiahong and Zhu, Xiangqi and Lu, Ning and Ieee}, year={2015} } @inproceedings{yan_zhu_lu_2015, title={Smart hybrid house test systems in a solid-state transformer supplied microgrid}, DOI={10.1109/pesgm.2015.7286550}, abstractNote={This paper presents the design and setup, considerations, and preliminary results of an AC/DC hybrid smart house test system. Rapid growth of rooftop photovoltaic (PV) in distribution systems makes it viable to supply a residential home with both AC and DC power sources. Solid-state transformers (SST) used as energy routers for rerouting power during normal and emergency situations are being developed in the FREEDM center at North Carolina State University. To provide a load test system for studying the control and monitoring of such an SST supplied AC/DC mixed power supply system, an 1-SST AC/DC hybrid smart house test system is built. The test system consists of a solid state transformer (SST), on-site photovoltaic panels, energy storage devices and three AC/DC smart houses with a home energy management system (HEMS). A demonstration case is presented to illustrate the operation of the test system for algorithm development and validation.}, booktitle={2015 ieee power & energy society general meeting}, author={Yan, J. H. and Zhu, X. Q. and Lu, N.}, year={2015} } @article{wang_jia_wang_lu_fan_zhou_qi_2015, title={Voltage stability enhancement using thermostatically controlled appliances as a comfort-constrained virtual generator}, volume={25}, ISSN={["2050-7038"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000367676900018&KeyUID=WOS:000367676900018}, DOI={10.1002/etep.2048}, abstractNote={Summary Conventional direct load-shedding for achieving static voltage stability lacks considerations on both customer comfort and energy efficiency, resulting in higher cost and emission. A novel security-based, optimal load-shedding strategy considering customer comfort settings is presented in this paper. A temperature priority list method is used to model the virtual generator (VG) consisting of thermostatically controlled appliances (TCAs). To illustrate the control process and performance evaluation of the proposed load-shedding scheme, a modified IEEE 6-bus test system is used. Three heat, ventilation, and air-conditioning (HVAC) groups are numerically simulated to respond to optimal load shedding signals. Reduced responsive load population, variations of temperature dead-bands, and different outdoor temperature profiles are modeled to evaluate the capacity variations of the VG and its control performance. The results demonstrate that TCAs can provide satisfactory voltage stability. Copyright © 2015 John Wiley & Sons, Ltd.}, number={12}, journal={INTERNATIONAL TRANSACTIONS ON ELECTRICAL ENERGY SYSTEMS}, author={Wang, Dan and Jia, Hongjie and Wang, Chengshan and Lu, Ning and Fan, Menghua and Zhou, Yue and Qi, Yebai}, year={2015}, month={Dec}, pages={3509–3522} } @article{jin_lu_lu_makarov_dougal_2014, title={A Coordinating Algorithm for Dispatching Regulation Services Between Slow and Fast Power Regulating Resources}, volume={5}, ISSN={["1949-3061"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000331985300053&KeyUID=WOS:000331985300053}, DOI={10.1109/tsg.2013.2277974}, abstractNote={This paper presents a novel coordinating algorithm for dispatching regulation services between slow and fast power regulating resources using a conventional power generator and a flywheel energy storage system as an example. The goal is to let the flywheel storage device follow the fast changes in the regulation signal and let the conventional generator compensate for the energy imbalance when the flywheel storage is nearly fully charged or discharged. A state-of-charge (SOC) band control algorithm is developed to maintain the storage device SOC within a desired range. Real system regulation signals were used to test the performance of the coordinating algorithm. The simulation results show that: 1) the HRR achieves the same fast response rate as that of the storage device, 2) the up and down movements of the generator are minimized, and 3) the SOC of the storage device is maintained within the desired range most of the time. Therefore, the proposed coordinating algorithm can provide the high quality regulation service while reducing maintenance-inducing strain on conventional generators.}, number={2}, journal={IEEE TRANSACTIONS ON SMART GRID}, author={Jin, Chunlian and Lu, Ning and Lu, Shuai and Makarov, Yuri V. and Dougal, Roger A.}, year={2014}, month={Mar}, pages={1043–1050} } @article{wang_ge_jia_wang_zhou_lu_kong_2014, title={A Demand Response and Battery Storage Coordination Algorithm for Providing Microgrid Tie-Line Smoothing Services}, volume={5}, ISSN={["1949-3029"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000333287200014&KeyUID=WOS:000333287200014}, DOI={10.1109/tste.2013.2293772}, abstractNote={This paper presents a demand response (DR) and battery storage coordination algorithm for providing microgrid tie-line smoothing services. A modified coordinating control strategy is implemented through two-way communication networks to manage distributed heat pumps in a microgrid for smoothing the tie-line (connect the microgrid to the main grid) power fluctuations. A total of 1000 residential electric heat pumps and a battery storage system are modeled to demonstrate the effectiveness and robustness of the proposed algorithm. The impact of outdoor temperature changes and customer room temperature preferences is considered in the simulation. The results show that coordinating with DR programs can significantly reduce the size of conventional energy storage systems for large-scale integration of renewable generation resources in microgrids and improve the power quality.}, number={2}, journal={IEEE TRANSACTIONS ON SUSTAINABLE ENERGY}, author={Wang, Dan and Ge, Shaoyun and Jia, Hongjie and Wang, Chengshan and Zhou, Yue and Lu, Ning and Kong, Xiangyu}, year={2014}, month={Apr}, pages={476–486} } @inbook{ke_lu_jin_ieee_2014, title={Control and Size Energy Storage for Managing Energy balance of Variable Generation Resources}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000349551504018&KeyUID=WOS:000349551504018}, booktitle={2014 Ieee Pes General Meeting - Conference & Exposition}, author={Ke, Xinda and Lu, Ning and Jin, Chunlian and Ieee}, year={2014} } @inproceedings{ke_lu_jin_2014, title={Control and size energy storage for managing energy balance of variable generation resources}, DOI={10.1109/pesgm.2014.6939484}, abstractNote={This paper presents control algorithms and sizing strategies for using energy storage to manage energy balance for variable generation resources. The control objective is to minimize the hourly generation imbalance between the actual and the scheduled generation of the wind farm. Three control algorithms are compared: tracking power imbalance, post-compensation, and pre-compensation. Measurement data from a wind farm located in South-central Washington State are used in the study. The results show that tracking power imbalance yields the best performance by keeping the hourly energy imbalances zero. However, the energy storage system (ESS) will be significantly oversized. Post-compensation reduces power rating of the ESS but the hourly imbalance may not be kept as zero when large and long-lasting energy imbalances occur. A linear regression forecasting algorithm is developed for the pre-compensation algorithm to pre-charge or pre-discharge the ESS based on predicted energy imbalances. The performance comparison shows that the pre-compensation method significantly reduces the size of the ESS while maintaining satisfactory performance.}, booktitle={2014 ieee pes general meeting - conference & exposition}, author={Ke, X. D. and Lu, N. and Jin, C. L.}, year={2014} } @book{du_lu_2014, title={Energy Storage for Smart Grids: Planning and Operation for Renewable and Variable Energy Resources}, ISBN={9780124104914}, url={http://dx.doi.org/10.1016/c2012-0-06954-2}, DOI={10.1016/c2012-0-06954-2}, abstractNote={This paper deals with one part of so called SMART GRIDS systems, which is storage of electrical and thermal energy, preferably in small scale applications, such as family houses, apartment houses or small commercial buildings. Distributed energy storage systems in combination with advanced power electronics will play a great technical role and it will have a huge impact on the electrical supply systems in the future and it should lead to many economical benefits.}, publisher={Elsevier}, author={Du, Pengwei and Lu, Ning}, year={2014} } @article{du_lu_wang_zhang_masiello_henderson_2014, title={Introduction to the Special Section on Energy Storage Applications for Smart Grid}, volume={5}, ISSN={["1949-3053"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000331985300041&KeyUID=WOS:000331985300041}, DOI={10.1109/tsg.2014.2305312}, abstractNote={This aim of this special section is to present applications of electrical energy storage. The issue summarizes the most recent research and development and it identifies issues that must be addressed for the successful application of storage technologies. We were extremely impressed by the number of papers submitted in response to the call for papers and the spectrum of interests that the international community has for energy storage. The papers solicited discuss a broad range of environmental, economic, technical, market, and policy considerations associated with the application of energy storage on power systems. Out of 83 submissions, we were able to accept 22 exceptional contributions. The final paper selection was made based on the quality of the papers and an attempt to balance a broad topical representation. The final papers were divided into five topical areas as follows: 1) Hybrid Storage Management System and its Applications in Microgrids; 2) Storage for Active Distribution Networks; 3) Energy Storage for Provision of Ancillary Services; 4) Energy Storage for Integration of Renewable Resources; and 5) Operation of Energy Storage for Reliability.}, number={2}, journal={IEEE TRANSACTIONS ON SMART GRID}, author={Du, Pengwei and Lu, Ning and Wang, Jianhui and Zhang, Xiao-Ping and Masiello, Ralph and Henderson, Mike}, year={2014}, month={Mar}, pages={935–936} } @book{hafen_samaan_makarov_diao_lu_ieee_2014, title={Joint Seasonal ARMA Approach for Modeling of Load Forecast Errors in Planning Studies}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000370376900003&KeyUID=WOS:000370376900003}, journal={2014 Ieee Pes T&D Conference and Exposition}, author={Hafen, Ryan P. and Samaan, Nader and Makarov, Yuri V. and Diao, Ruisheng and Lu, Ning and Ieee}, year={2014} } @book{vanouni_lu_ieee_2014, title={Performance Indices for Evaluating Demand Response Services Provided by Thermostatically Controlled Appliances}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000370376900207&KeyUID=WOS:000370376900207}, journal={2014 Ieee Pes T&D Conference and Exposition}, author={Vanouni, Maziar and Lu, Ning and Ieee}, year={2014} } @article{wang_jia_wang_lu_fan_miao_liu_2014, title={Performance evaluation of controlling thermostatically controlled appliances as virtual generators using comfort-constrained state-queueing models}, volume={8}, ISSN={["1751-8695"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000333641800002&KeyUID=WOS:000333641800002}, DOI={10.1049/iet-gtd.2013.0093}, abstractNote={This study presents a detailed performance evaluation of comfort-constrained state-queueing model for integration of thermostatically controlled appliances (TCAs) as virtual generators (VGs). The configuration of VG models is presented. The heating mode of heating, ventilating and air-conditioning (HVAC) unit – heat pump is used as an example TCA load to demonstrate VG operation. First, an estimated baseline of the aggregated HVAC loads is obtained based on outdoor temperature forecasts using thermal dynamic models. Then, the control method of HVAC units for intra-hour load balancing is proposed. The effects of different comfort-constraints, outdoor temperature profiles and thermal deadbands are modelled to evaluate the performance of TCAs as VGs. The technical functionality of the TCA-VG is described and demonstrated by the modelling results.}, number={4}, journal={IET GENERATION TRANSMISSION & DISTRIBUTION}, author={Wang, Dan and Jia, Hongjie and Wang, Chengshan and Lu, Ning and Fan, Menghua and Miao, Weiwei and Liu, Zhe}, year={2014}, month={Apr}, pages={591–599} } @inbook{lu_diao_hafen_samaan_makarov_ieee_2013, title={A Comparison of Forecast Error Generators for Modeling Wind and Load Uncertainty}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000331874303159&KeyUID=WOS:000331874303159}, booktitle={2013 Ieee Power and Energy Society General Meeting}, author={Lu, Ning and Diao, Ruisheng and Hafen, Ryan P. and Samaan, Nader and Makarov, Yuri V. and Ieee}, year={2013} } @inproceedings{lu_diao_hafen_samaan_makarov_2013, title={A comparison of forecast error generators for modeling wind and load uncertainty}, DOI={10.1109/pesmg.2013.6672978}, abstractNote={This paper presents four algorithms to generate random forecast error time series, including a truncated-normal distribution model, a state-space based Markov model, a seasonal autoregressive moving average (ARMA) model, and a stochastic-optimization based model. The error time series are used to create real-time (RT), hour-ahead (HA), and day-ahead (DA) wind and load forecast time series that statistically match historically observed forecasting data sets, used for variable generation integration studies. A comparison is made using historical DA load forecast and actual load values to generate new sets of DA forecasts with similar stoical forecast error characteristics. This paper discusses and compares the capabilities of each algorithm to preserve the characteristics of the historical forecast data sets.}, booktitle={2013 ieee power and energy society general meeting (pes)}, author={Lu, N. and Diao, R. S. and Hafen, R. P. and Samaan, N. and Makarov, Y. V.}, year={2013} } @book{zhang_lu_ieee_2013, title={Demand-side Management of Air Conditioning Cooling Loads for Intra-hour Load Balancing}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000320500800116&KeyUID=WOS:000320500800116}, journal={2013 Ieee Pes Innovative Smart Grid Technologies}, author={Zhang, Yu and Lu, Ning and Ieee}, year={2013} } @article{lu_zhang_2013, title={Design Considerations of a Centralized Load Controller Using Thermostatically Controlled Appliances for Continuous Regulation Reserves}, volume={4}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000325487800029&KeyUID=WOS:000325487800029}, DOI={10.1109/tsg.2012.2222944}, abstractNote={This paper presents design considerations for a centralized load controller to control thermostatically controlled appliances (TCAs) for continuous regulation reserves (CRRs). The controller logics for setting up the baseline load, generating priority lists, issuing dispatch commands, and tuning the simplified forecaster model using measurement data are described. To study the impacts of different control parameter settings on control performance and device lifetimes, a system consisting of 1000 heating, ventilating, and air-conditioning (HVAC) units in their heating modes is modeled to provide a CRR 24 hours a day. Four cases are modeled to evaluate the impact of forecasting errors, minimum HVAC turn-off times, response delays, and consumer overrides. The results demonstrate that a centralized TCA load controller can provide robust, good quality CRRs with reduced communication needs for the two-way communication network and inexpensive load control devices. Most importantly, because the controller precisely controls the aggregated HVAC load shapes while maintaining load diversity, the controllable and measurable load services that it provides can be used for many other demand response applications, such as peak shaving, load shifting, and arbitrage.}, number={2}, journal={Ieee Transactions on Smart Grid}, author={Lu, Ning and Zhang, Yu}, year={2013}, pages={914–921} } @inbook{lu_ieee_2013, title={Design Considerations of a Centralized Load Controller Using Thermostatically Controlled Appliances for Continuous Regulation Reserves}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000331874300120&KeyUID=WOS:000331874300120}, booktitle={2013 Ieee Power and Energy Society General Meeting}, author={Lu, Ning and Ieee}, year={2013} } @inproceedings{lu_2013, title={Design considerations of a centralized load controller using thermostatically controlled appliances for continuous regulation reserves}, DOI={10.1109/pesmg.2013.6672203}, abstractNote={This paper presents design considerations for a centralized load controller to control thermostatically controlled appliances (TCAs) for continuous regulation reserves (CRRs). The controller logics for setting up the baseline load, generating priority lists, issuing dispatch commands, and tuning the simplified forecaster model using measurement data are described. To study the impacts of different control parameter settings on control performance and device lifetimes, a system consisting of 1000 heating, ventilating, and air-conditioning (HVAC) units in their heating modes is modeled to provide a ±1-MW CRR 24 hours a day. Four cases are modeled to evaluate the impact of forecasting errors, minimum HVAC turn-off times, response delays, and consumer overrides. The results demonstrate that a centralized TCA load controller can provide robust, good quality CRRs with reduced communication needs for the two-way communication network and inexpensive load control devices. Most importantly, because the controller precisely controls the aggregated HVAC load shapes while maintaining load diversity, the controllable and measurable load services that it provides can be used for many other demand response applications, such as peak shaving, load shifting, and arbitrage.}, booktitle={2013 ieee power and energy society general meeting (pes)}, author={Lu, N.}, year={2013} } @article{zhang_lu_2013, title={Parameter Selection for a Centralized Thermostatically Controlled Appliances Load Controller Used for Intra-Hour Load Balancing}, volume={4}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000328064100038&KeyUID=WOS:000328064100038}, DOI={10.1109/tsg.2013.2258950}, abstractNote={This paper presents a novel dynamic parameter selection process to optimize the performance of a centralized load controller designed to provide intra-hour load balancing services using thermostatically controlled appliances (TCAs). An optimal set of control parameters for the controller are selected by exhaustive simulations of control variables such as the sampling time of the forecaster, the magnitude of the load balancing signal, and the temperature deadband. The effects of TCA lock-off times, ambient temperatures, heat gains, and two-way communication delays on the controller design are also modeled. Customer comfort, device life cycles, and control errors are used as metrics to evaluate the performance. The results demonstrate that the optimized controller offers satisfactory performance considering all the operational uncertainties.}, number={4}, journal={Ieee Transactions on Smart Grid}, author={Zhang, Yu and Lu, Ning}, year={2013}, pages={2100–2108} } @article{lu_vanouni_2013, title={Passive energy storage using distributed electric loads with thermal storage}, volume={1}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000209527300009&KeyUID=WOS:000209527300009}, DOI={10.1007/s40565-013-0033-z}, abstractNote={This paper presents the concept of controlling distributed electric loads with thermal energy storage as a passive electric energy storage system (PEESS). Examples of such loads include different types of thermostatically controlled appliances (TCAs) such as hot water heaters, air conditioners, and refrigerators. Each TCA can be viewed as a thermal cell that stores electricity as thermal energy. A centralized control mechanism can be used to control the timing of each thermal cell to consume electric energy so that the aggregated electricity consumption of the thermal cells will vary against a baseline consumption. Thus, when the aggregated consumption is higher than the baseline, the PEESS is charging; otherwise, the PEESS is discharging. The overall performance of a PEESS will be equivalent to that of a battery energy storage device. This paper presents the configuration and formulates the control of a PEESS. The modeling results demonstrate the feasibility of implementing the PEESS.}, number={3}, journal={Journal of Modern Power Systems and Clean Energy}, author={Lu, Ning and Vanouni, Maziar}, year={2013}, pages={264–274} } @article{zheng_lu_cai_2013, title={Reliable Wireless Communication Networks for Demand Response Control}, volume={4}, ISSN={["1949-3061"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000325485600013&KeyUID=WOS:000325485600013}, DOI={10.1109/tsg.2012.2224892}, abstractNote={This paper presents methodologies for deriving reliability performance of wireless communication networks to support demand response (DR) control. First, the impact of communication impairments on a direct DR control program is investigated. Second, the outage probability of a wireless link is modelled and quantified, considering the multipath fading, shadowing, and random path loss given the location distribution of smart meters. Third, the distributions of packet delivery ratio are derived for two wireless network architectures: the single-hop infrastructure-based network and the multi-hop mesh network. Simulation results verify the above reliability models and provide important insights on the coverage of wireless communication networks considering the reliability requirements of DR programs.}, number={1}, journal={IEEE TRANSACTIONS ON SMART GRID}, author={Zheng, Lei and Lu, Ning and Cai, Lin}, year={2013}, month={Mar}, pages={133–140} } @inbook{lu_du_greitzer_guo_hohimer_pomiak_ieee_2012, title={A Multi-layer, Data-driven Advanced Reasoning Tool for Intelligent Data Mining and Analysis for Smart Grids}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000312493704028&KeyUID=WOS:000312493704028}, booktitle={2012 Ieee Power and Energy Society General Meeting}, author={Lu, Ning and Du, Pengwei and Greitzer, Frank L. and Guo, Xinxin and Hohimer, Ryan E. and Pomiak, Yekaterina G. and Ieee}, year={2012} } @article{lu_2012, title={An Evaluation of the HVAC Load Potential for Providing Load Balancing Service}, volume={3}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000325484500020&KeyUID=WOS:000325484500020}, DOI={10.1109/tsg.2012.2183649}, abstractNote={This paper investigates the potential of providing intra-hour load balancing services using aggregated heating, ventilating, and air-conditioning (HVAC) loads. A directload control algorithm is presented. A temperature-priority-list method is used to dispatch the HVAC loads optimally to maintain customer-desired indoor temperatures and load diversity. Realistic intra-hour load balancing signals are used to evaluate the operational characteristics of the HVAC load under different outdoor temperature profiles and different indoor temperature settings. The number of HVAC units needed is also investigated. Modeling results suggest that the number of HVAC units needed to provide a ±1-MW load balancing service 24 hours a day varies significantly with baseline settings, high and low temperature settings, and outdoor temperatures. The results demonstrate that the intra-hour load balancing service provided by HVAC loads meets the performance requirements and can become a major source of revenue for load-serving entities where the two-way communication smart grid infrastructure enables direct load control over the HVAC loads.}, number={3}, journal={Ieee Transactions on Smart Grid}, author={Lu, Ning}, year={2012}, pages={1263–1270} } @book{lesieutre_bravo_yinger_chassin_huang_lu_hiskens_venkataramanan_2012, title={Final Project Report Load Modeling Transmission Research}, url={http://dx.doi.org/10.2172/1183173}, DOI={10.2172/1183173}, abstractNote={FINAL PROJECT REPORT LOAD MODELING TRANSMISSION RESEARCH Prepared for CIEE By: Lawrence Berkeley National Laboratory Project Manager: Bernard Lesieutre Authors: Richard Bravo, Robert Yinger, Dave Chassin, Henry Huang, Ning Lu, Ian Hiskens, Giri Venkataramanan Date: March, 2010 A CIEE Report}, institution={Office of Scientific and Technical Information (OSTI)}, author={Lesieutre, Bernard and Bravo, Richard and Yinger, Robert and Chassin, Dave and Huang, Henry and Lu, Ning and Hiskens, Ian and Venkataramanan, Giri}, year={2012}, month={Mar} } @inbook{makarov_etingov_samaan_lu_ma_subbarao_du_kannberg_ieee_2012, title={Improving Performance of Power Systems with Large-scale Variable Generation Additions}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000312493705101&KeyUID=WOS:000312493705101}, booktitle={2012 Ieee Power and Energy Society General Meeting}, author={Makarov, Yuri V. and Etingov, Pavel V. and Samaan, Nader A. and Lu, Ning and Ma, Jian and Subbarao, Krishnappa and Du, Pengwei and Kannberg, Landis D. and Ieee}, year={2012} } @article{wang_liu_lu_2012, title={Micro-Grid Tie-line Power Smoothing using Demand Response Program}, volume={25}, number={32}, journal={Proceedings of the CSEE}, author={Wang, Chenshan and Liu, Mengxuan and Lu, N.}, year={2012}, pages={36–43} } @book{lu_du_guo_greitzer_ieee_2012, title={Smart Meter Data Analysis}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000317001100198&KeyUID=WOS:000317001100198}, journal={2012 Ieee Pes Transmission and Distribution Conference and Exposition}, author={Lu, Ning and Du, Pengwei and Guo, Xinxin and Greitzer, Frank L. and Ieee, P. E. S.}, year={2012} } @inbook{lu_du_makarov_ieee_2012, title={The Potential of Thermostatically Controlled Appliances for Intra-hour Energy Storage Applicationst}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000312493703097&KeyUID=WOS:000312493703097}, booktitle={2012 Ieee Power and Energy Society General Meeting}, author={Lu, Ning and Du, Pengwei and Makarov, Yuri V. and Ieee}, year={2012} } @book{du_lu_ieee_2012, title={appliance commitment for household load scheduling}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000317001100061&KeyUID=WOS:000317001100061}, journal={2012 Ieee Pes Transmission and Distribution Conference and Exposition}, author={Du, Pengwei and Lu, Ning and Ieee, P. E. S.}, year={2012} } @inbook{lu_du_paulson_greitzer_guo_hadley_ieee_2011, title={A Multi-layer, Hierarchical Information Management System for the Smart Grid}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000297469602029&KeyUID=WOS:000297469602029}, booktitle={2011 Ieee Power and Energy Society General Meeting}, author={Lu, Ning and Du, Pengwei and Paulson, Patrick and Greitzer, Frank and Guo, Xinxin and Hadley, Mark and Ieee}, year={2011} } @article{kondoh_lu_hammerstrom_2011, title={An Evaluation of the Water Heater Load Potential for Providing Regulation Service}, volume={26}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000293711700035&KeyUID=WOS:000293711700035}, DOI={10.1109/tpwrs.2010.2090909}, abstractNote={This paper investigates the possibility of providing aggregated regulation services with small loads, such as water heaters or air conditioners. A direct-load control algorithm is presented to aggregate the water heater load for the purpose of regulation. A dual-element electric water heater model is developed, which accounts for both thermal dynamics and users' water consumption. A realistic regulation signal was used to evaluate the number of water heaters needed and the operational characteristics of a water heater when providing 2-MW regulation service. Modeling results suggest that approximately 33, 000 water heaters are needed to provide a 2-MW regulation service 24 hours a day. However, if water heaters only provide regulation from 6:00 to 24:00, approximately 20, 000 will be needed. Because the control algorithm has considered the thermal setting of the water heater, customer comfort is maintained. Therefore, the aggregated regulation service provided by water heater loads can become a major source of revenue for load-serving entities when the smart grid enables the direct load control.}, number={3}, journal={Ieee Transactions on Power Systems}, author={Kondoh, Junji and Lu, Ning and Hammerstrom, Donald J.}, year={2011}, pages={1309–1316} } @inbook{kondoh_lu_hammerstrom_ieee_2011, title={An Evaluation of the Water Heater Load Potential for Providing Regulation Service}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000297469601115&KeyUID=WOS:000297469601115}, booktitle={2011 Ieee Power and Energy Society General Meeting}, author={Kondoh, Junji and Lu, Ning and Hammerstrom, Donald J. and Ieee}, year={2011} } @inproceedings{lu_weimar_makarov_loutan_2011, title={An evaluation of the NaS battery storage potential for providing regulation service in California}, ISBN={9781612847894}, url={http://dx.doi.org/10.1109/psce.2011.5772494}, DOI={10.1109/psce.2011.5772494}, abstractNote={Sodium sulfur (NaS) batteries can provide energy storage, real-time dispatch, regulation, frequency response, and other essential services to the power grids. This study presents the technical characteristics, modeling approach, methodologies, and results for providing regulation services in the California Independent System Operator (CAISO) market. Two different scenarios were studied and compared: a scenario without intermittent renewable-energy resource penetration (base case) and a scenario with significant renewable-energy resource penetration (including wind) reaching 20% of CAISO's energy supply. In addition, breakeven cost analyses were developed for four cases. Based on the results of the technical and cost analyses, the opportunities for the NaS battery providing the regulation services are discussed, design improvements for the battery's physical characteristics are recommended, and modifications of the regulation signals sent to NaS batteries are proposed.}, booktitle={2011 IEEE/PES Power Systems Conference and Exposition}, publisher={IEEE}, author={Lu, N. and Weimar, M. R. and Makarov, Y. V. and Loutan, C.}, year={2011}, month={Mar} } @article{mello_lu_makarov_2011, title={An optimized autoregressive forecast error generator for wind and load uncertainty study}, volume={14}, ISSN={1095-4244}, url={http://dx.doi.org/10.1002/we.460}, DOI={10.1002/we.460}, abstractNote={ABSTRACT}, number={8}, journal={Wind Energy}, publisher={Wiley}, author={Mello, Phillip E. and Lu, Ning and Makarov, Yuri}, year={2011}, month={Feb}, pages={967–976} } @article{du_lu_2011, title={Appliance Commitment for Household Load Scheduling}, volume={2}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000208787500019&KeyUID=WOS:000208787500019}, DOI={10.1109/tsg.2011.2140344}, abstractNote={This paper presents a novel appliance commitment algorithm that schedules thermostatically controlled household loads based on price and consumption forecasts considering users' comfort settings to meet an optimization objective such as minimum payment or maximum comfort. The formulation of an appliance commitment problem is described using an electrical water heater load as an example. The thermal dynamics of heating and coasting of the water heater load is modeled by physical models; random hot water consumption is modeled with statistical methods. The models are used to predict the appliance operation over the scheduling time horizon. User comfort is transformed to a set of linear constraints. Then, a novel linear-sequential-optimization-enhanced, multiloop algorithm is used to solve the appliance commitment problem. The simulation results demonstrate that the algorithm is fast, robust, and flexible. The algorithm can be used in home/building energy-management systems to help household owners or building managers to automatically create optimal load operation schedules based on different cost and comfort settings and compare cost/benefits among schedules.}, number={2}, journal={Ieee Transactions on Smart Grid}, author={Du, Pengwei and Lu, Ning}, year={2011}, pages={411–419} } @inbook{jin_lu_lu_makarov_dougal_ieee_2011, title={Coordinated Control Algorithm for Hybrid Energy Storage Systems}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000297469606093&KeyUID=WOS:000297469606093}, booktitle={2011 Ieee Power and Energy Society General Meeting}, author={Jin, Chunlian and Lu, Ning and Lu, Shuai and Makarov, Yuri and Dougal, Roger A. and Ieee}, year={2011} } @inbook{jin_lu_lu_dougal_ieee_2011, title={Cross-Market Optimization for Hybrid Energy Storage Systems}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000297469606098&KeyUID=WOS:000297469606098}, booktitle={2011 Ieee Power and Energy Society General Meeting}, author={Jin, Chunlian and Lu, Shuai and Lu, Ning and Dougal, Roger A. and Ieee}, year={2011} } @inbook{makarov_lu_samaan_huang_subbarao_etingov_ma_hafen_diao_lu_et al._2011, title={Integration of Uncertainty Information into Power System Operations}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000297469606111&KeyUID=WOS:000297469606111}, booktitle={2011 Ieee Power and Energy Society General Meeting}, author={Makarov, Yuri V. and Lu, Shuai and Samaan, Nader and Huang, Zhenyu and Subbarao, Krishnappa and Etingov, Pavel V. and Ma, Jian and Hafen, Ryan P. and Diao, Ruisheng and Lu, Ning and et al.}, year={2011} } @inbook{nguyen_lu_jin_ieee_2011, title={Modeling Impacts of Climate Change Mitigation Technologies on Power Grids}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000297469605124&KeyUID=WOS:000297469605124}, booktitle={2011 Ieee Power and Energy Society General Meeting}, author={Nguyen, Tony B. and Lu, Ning and Jin, Chunlian and Ieee}, year={2011} } @inproceedings{jin_lu_lu_makarov_dougal_2011, place={Piscataway, NJ}, title={Novel Dispatch Algorithm for Regulation Service using a Hybrid Energy Storage System}, booktitle={2011 IEEE PES General Meeting : "the electrification of transportation & the grid of the future" 24-28 July 2011, Detroit, MI, USA}, publisher={IEEE}, author={Jin, C. and Lu, N. and Lu, S. and Makarov, Y.V. and Dougal, R.A.}, year={2011} } @inbook{lu_du_paulson_greitzer_guo_hadley_ieee_2011, title={The Development of a Smart Distribution Grid Testbed for Integrated Information Management Systems}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000297469600008&KeyUID=WOS:000297469600008}, booktitle={2011 Ieee Power and Energy Society General Meeting}, author={Lu, Ning and Du, Pengwei and Paulson, Patrick and Greitzer, Frank L. and Guo, Xinxin and Hadley, Mark and Ieee}, year={2011} } @inbook{lu_weimar_makarov_rudolph_murthy_arseneaux_loutan_ieee_2010, title={An Evaluation of the Flywheel Potential for Providing Regulation Service in California}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000287611901134&KeyUID=WOS:000287611901134}, booktitle={Ieee Power and Energy Society General Meeting 2010}, author={Lu, N. and Weimar, M. R. and Makarov, Y. V. and Rudolph, F. J. and Murthy, S. N. and Arseneaux, J. and Loutan, C. and Ieee}, year={2010} } @article{lu_taylor_jiang_jin_correia_leung_wong_2010, title={Climate Change Impacts on Residential and Commercial Loads in the Western US Grid}, volume={25}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000273930800050&KeyUID=WOS:000273930800050}, DOI={10.1109/tpwrs.2009.2030387}, abstractNote={ This paper presents a multidisciplinary modeling approach to quickly quantify climate change impacts on energy consumption, peak load, and load composition of residential and commercial buildings. This research focuses on addressing the impact of temperature changes on the building cooling load in ten major cities across the Western United States and Canada. Our results have shown that by the mid-century, building yearly energy consumption and peak load will increase in the Southwest. Moreover, the peak load months will spread out to not only the summer months but also spring and autumn months. The Pacific Northwest will experience more hot days in the summer months. The penetration levels of air-conditioning (a/c) systems in this region are likely to increase significantly over the years. As a result, some locations in the Pacific Northwest may be shifted from winter peaking to summer peaking. Overall, the Western U.S. grid may see more simultaneous peaks across the North and South in summer months. Increased cooling load will result in a significant increase in the motor load, which consumes more reactive power and requires stronger voltage support from the grid. This study suggests an increasing need for the industry to implement new technology to increase the efficiency of temperature-sensitive loads and apply proper protection and control to prevent possible adverse impacts of a/c motor loads. }, number={1}, journal={Ieee Transactions on Power Systems}, author={Lu, Ning and Taylor, Todd and Jiang, Wei and Jin, Chunlian and Correia, James, Jr. and Leung, L. Ruby and Wong, Pak Chung}, year={2010}, pages={480–488} } @article{khurana_hadley_lu_frincke_2010, title={Smart-Grid Security Issues}, volume={8}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000274527500016&KeyUID=WOS:000274527500016}, DOI={10.1109/msp.2010.49}, abstractNote={This article has given a broadbrush description of issues related to smart-grid security. Designing solutions in at this stage, before widespread deployment, would be beneficial; in some cases solutions exist, whereas in others research investments will be needed. Several open questions about goals still require discussion, especially around such topics as how (and how much) privacy can be supported.}, number={1}, journal={Ieee Security & Privacy}, author={Khurana, Himanshu and Hadley, Mark and Lu, Ning and Frincke, Deborah A.}, year={2010}, pages={81–85} } @book{lu_makarov_weimar_rudolph_murthy_arseneaux_loutan_chowdhury_2010, title={THE WIDE-AREA ENERGY STORAGE AND MANAGEMENT SYSTEM PHASE II Final Report - Flywheel Field Tests}, url={http://dx.doi.org/10.2172/991592}, DOI={10.2172/991592}, abstractNote={Independent System Operator, for providing the project team with organizational support, advice, and guidance essential to this work. Abstract The higher penetration of intermittent generation resources (including wind and solar generation) in the Bonneville Power Administration (BPA) and California Independent System Operator (CAISO) balancing authorities (BAs) raises the issue of requiring expensive additional fast grid balancing services in response to additional intermittency and fast up and down power ramps in the electric power system. The overall goal of the wide-area energy management system (WAEMS) project is to develop the principles, algorithms, market integration rules, a functional design, and technical specifications for an energy storage system to cope with uncertainties and unexpected rapid changes in renewable generation power output. The resulting WAEMS system will store excess energy, control dispatchable load and distributed generation, and use inter-area exchange of the excess energy between the CAISO and BPA BAs. A further goal is to provide a cost-benefit analysis and develop a business model for an investment-based practical deployment of such a system. A major goal of the WAEMS project is to minimize the balancing effort by developing a centralized control system that operates energy storage devices in conjunction with conventional generators to provide fast balancing services that can be shared among balancing authorities. The idea is based on coordination of traditional services (provided by conventional generation) and energy storage. In Phase II of the project described in this report, a prototype WAEMS configuration consisting of a hydro electric plant and a flywheel energy storage was field tested using actual area-control-error and regulation signals provided by BPA and CAISO. The results were used to evaluate the performance and economics of the flywheel-hydro regulation service. The performance evaluation shows an excellent performance of the WAEMS control algorithm, which separates the faster regulation effort provided by the energy storage from the slower one provided by a conventional regulating unit. The WAEMS combined service is not strictly constrained by energy storage limits because the hydro plant supports the desired flywheel's energy level. In addition, the WAEMS combined service has the same fast-response characteristic (within 6 seconds) as that provided by the flywheel energy storage alone. Furthermore, the WAEMS control algorithm reduces wear and tear on the hydro unit and allows the hydro unit to operate closer to its preferred operating point. The breakeven price for flywheel energy storage to provide bi-directional service (1 MW regulation-up and ± …}, institution={Office of Scientific and Technical Information (OSTI)}, author={Lu, Ning and Makarov, Yuri V. and Weimar, Mark R. and Rudolph, Frank and Murthy, Shashikala and Arseneaux, Jim and Loutan, Clyde and Chowdhury, S.}, year={2010}, month={Aug} } @book{lu_makarov_weimar_2010, title={The Wide-area Energy Management System Phase 2 Final Report}, url={http://dx.doi.org/10.2172/1000162}, DOI={10.2172/1000162}, abstractNote={The higher penetration of intermittent generation resources (including wind and solar generation) in the Bonneville Power Administration (BPA) and California Independent System Operator (CAISO) balancing authorities (BAs) raises issue of requiring expensive additional fast grid balancing services in response to additional intermittency and fast up and down power ramps in the electric supply system. The overall goal of the wide-area energy management system (WAEMS) project is to develop the principles, algorithms, market integration rules, a functional design, and a technical specification for an energy storage system to help cope with unexpected rapid changes in renewable generation power output. The resulting system will store excess energy, control dispatchable load and distributed generation, and utilize inter-area exchange of the excess energy between the California ISO and Bonneville Power Administration control areas. A further goal is to provide a cost-benefit analysis and develop a business model for an investment-based practical deployment of such a system. There are two tasks in Phase 2 of the WAEMS project: the flywheel field tests and the battery evaluation. Two final reports, the Wide-area Energy Management System Phase 2 Flywheel Field Tests Final Report and the Wide-area Energy Storage and Management System Battery Storage Evaluation, were written tomore » summarize the results of the two tasks.« less}, institution={Office of Scientific and Technical Information (OSTI)}, author={Lu, Ning and Makarov, Yuri V. and Weimar, Mark R.}, year={2010}, month={Aug} } @inbook{lu_makarov_zhu_lu_kumar_chakrabarti_ieee_2010, title={Unit Commitment Considering Generation Flexibility and Environmental Constraints}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000287611905101&KeyUID=WOS:000287611905101}, booktitle={Ieee Power and Energy Society General Meeting 2010}, author={Lu, Shuai and Makarov, Yuri V. and Zhu, Yunhua and Lu, Ning and Kumar, Nirupama Prakash and Chakrabarti, Bhujanga B. and Ieee}, year={2010} } @article{wong_leung_lu_scott_mackey_foote_correia_taylor_xu_unwin_et al._2009, title={Designing a Collaborative Visual Analytics Tool for Social and Technological Change Prediction}, volume={29}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000269517400008&KeyUID=WOS:000269517400008}, DOI={10.1109/mcg.2009.92}, abstractNote={This paper discussed about GreenOracle which an interdisciplinary team designed and developed. GreenOracle is a collaborative visual analytics tool for predicting global climate change's impact on US power grids and its implications for society and national security. These future scenarios provide critical assessments and information to help policymakers and stakeholders formulate a coherent and unified strategy toward shaping a safe and secure society.}, number={5}, journal={Ieee Computer Graphics and Applications}, author={Wong, Pak Chung and Leung, L. Ruby and Lu, Ning and Scott, Michael J. and Mackey, Patrick and Foote, Harlan and Correia, James, Jr. and Taylor, Z. Todd and Xu, Jianhua and Unwin, Stephen D. and et al.}, year={2009}, pages={58–68} } @article{lu_chow_desrochers_2009, title={Generator bidding strategies in a competitive electricity market with derating and bid-segment considerations}, volume={29}, DOI={10.2316/journal.203.2009.3.203-3590}, abstractNote={This paper develops optimal generator bidding strategies in a competitive electricity market. Starting from a generator’s cost curve, basic bidding concepts such as the break-even bid curve and the maximum profit bid curve can be readily derived. The maximum profit bid curve can be extended to account for generator availability and derating. In addition, multiple-segment block energy bids can be optimized based on the maximum profit curve and the probabilistic distribution of market clearing prices.}, number={3}, journal={International Journal of Electrical Power & Energy Systems}, author={Lu, N. and Chow, J.H. and Desrochers, A.A.}, year={2009}, pages={173–180} } @book{lu_hammerstrom_patrick_2009, title={Grid FriendlyTM Device Model Development and Simulation}, url={http://dx.doi.org/10.2172/974988}, DOI={10.2172/974988}, abstractNote={In late 2007, the Bonneville Power Administration (BPA) contracted Pacific Northwest National Laboratory (PNNL) to complete a research project titled Grid-Responsive Demand-Side Control Using Grid Friendly Appliance Technologies [Hammerstrom 2009, DeSteese and Hammerstrom 2009]. Cosponsors included Portland General Electric (PGE) and Puget Sound Energy (PSE). The project focused on applications of the Grid Friendly Appliance (GFA) controller, which is an autonomous controller that was designed to advise devices like appliances concerning valuable demand-side grid services that should be conducted. The controller bases its advice on observations it makes from the ac voltage signal. Electric tank water heaters were selected to be controlled by the GFA controller in this project. Two autonomous responses are addressed herein. First, an under-voltage-responsive water heater is able to recognize sudden reductions in feeder circuit voltage at each water heater and may curtail any electric load that is being consumed by the water heater. These under-voltage events are usually induced by nearby electrical faults. An under-voltage response is necessarily specified by the set of voltage thresholds at which the responsive water heaters would respond. The set of voltages at which the curtailment would be released must also be specified. Additionally, any delays prior to the water more » heater load becoming curtailed or again released must be specified. For example, a delay may be intentionally imposed prior to curtailing water heater loads to avoid responses during the fault itself. Much longer and randomized delays should be imposed prior to the release of curtailments in order to re-establish diversity of the water heater loads and soften what could otherwise be an abrupt reintroduction of a large aggregated electrical load into the already stressed grid region. « less}, institution={Office of Scientific and Technical Information (OSTI)}, author={Lu, Ning and Hammerstrom, Donald J. and Patrick, Stasha N.}, year={2009}, month={Dec} } @inproceedings{wong_leung_lu_paget_correia_jiang_mackey_taylor_xie_xu_et al._2009, place={Menlo Park, California}, title={Predicting the Impact of Climate Change on U.S. Power Grids and Its Wider Implications on National Security}, booktitle={Proceedings AAAI Spring Symposium on Technosocial Predictive Analytics 2009}, publisher={AAAI Press}, author={Wong, P.C. and Leung, L.R. and Lu, N. and Paget, M. and Correia, J., Jr. and Jiang, W. and Mackey, P. and Taylor, Z.T. and Xie, Y.L. and Xu, J. and et al.}, year={2009}, pages={148–153} } @book{lu_yang_huang_bravo_power_energy_2009, title={The System Impact of Air Conditioner Under-voltage Protection Schemes}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000271244500006&KeyUID=WOS:000271244500006}, journal={2009 Ieee/Pes Power Systems Conference and Exposition, Vols 1-3}, author={Lu, N. and Yang, B. and Huang, Z. and Bravo, R. and Power, Ieee and Energy, Soc}, year={2009}, pages={36-+} } @book{lu_weimar_makarov_ma_viswanathan_2009, place={Richland, Washington}, title={The Wide-Area Energy Storage and Management System -- Battery Storage Evaluation}, url={http://dx.doi.org/10.2172/969906}, DOI={10.2172/969906}, abstractNote={This report presents the modeling approach, methodologies, and results of the sodium sulfur (NaS) battery evaluation study, which was conducted by Battelle for the California Energy Commission (CEC).}, number={PNNL-18679PNNL-18679}, institution={Office of Scientific and Technical Information (OSTI)}, author={Lu, Ning and Weimar, Mark R. and Makarov, Yuri V. and Ma, Jian and Viswanathan, Vilayanur V.}, year={2009}, month={Jul} } @inproceedings{lu_yang_huang_bravo_2009, title={The system impact of air conditioner under-voltage protection schemes}, ISBN={9781424438105}, url={http://dx.doi.org/10.1109/psce.2009.4840053}, DOI={10.1109/psce.2009.4840053}, abstractNote={This paper presents the results of simulating and evaluating an under-voltage protection scheme, which takes stalled air-conditioner (a/c) units offline so that the slow voltage recovery phenomena can be prevented in areas heavily loaded with a/c motors during summer peak periods. First, a three-feeder test-bed was used to quantify the effectiveness of the protection scheme and the sensitivity of the under-voltage relay settings. Then, two real system events from the Western US power grid were simulated to evaluate the area-level impact of the protection scheme proposed by Southern California Edison. The study demonstrates that after 75% or more of the stalled a/c units are disconnected, the feeder voltage recovers in a few seconds, much quicker than the tens of seconds that standard thermal relays need to trip the stalled motor offline. The drawback is that after the voltage recovered, it settles at a higher value than prior to the faults because a large proportion of load is shed. Therefore, the coordination among the capacitor bank operation is recommended to suppress the overvoltage caused by tripping of the a/c motor load.}, booktitle={2009 IEEE/PES Power Systems Conference and Exposition}, publisher={IEEE}, author={Lu, N. and Yang, B. and Huang, Z. and Bravo, R.}, year={2009}, month={Mar} } @inproceedings{lu_taylor_jiang_correia_leung_wong_2009, title={The temperature sensitivity of the residential load and commercial building load}, ISBN={9781424442416}, url={http://dx.doi.org/10.1109/pes.2009.5275654}, DOI={10.1109/pes.2009.5275654}, abstractNote={This paper presents a building modeling approach to quickly quantify climate change impacts on energy consumption, peak load, and load composition of residential and commercial buildings. This research focuses on addressing the impact of temperature changes on the building heating and cooling load in 10 major cities across the Western United States and Canada. A building simulation software is first used to quantify the hourly energy consumption of different building types by end-use and by vintage. Then, the temperature sensitivities are derived based on the climate data inputs.}, booktitle={2009 IEEE Power & Energy Society General Meeting}, publisher={IEEE}, author={Lu, N. and Taylor, T. and Jiang, W. and Correia, J. and Leung, L.R. and Wong, P.C.}, year={2009}, month={Jul} } @book{lu_xie_huang_2008, title={Air Conditioner Compressor Performance Model}, url={http://dx.doi.org/10.2172/949142}, DOI={10.2172/949142}, abstractNote={During the past three years, the Western Electricity Coordinating Council (WECC) Load Modeling Task Force (LMTF) has led the effort to develop the new modeling approach. As part of this effort, the Bonneville Power Administration (BPA), Southern California Edison (SCE), and Electric Power Research Institute (EPRI) Solutions tested 27 residential air-conditioning units to assess their response to delayed voltage recovery transients. After completing these tests, different modeling approaches were proposed, among them a performance modeling approach that proved to be one of the three favored for its simplicity and ability to recreate different SVR events satisfactorily. Funded by the California Energy Commission (CEC) under its load modeling project, researchers at Pacific Northwest National Laboratory (PNNL) led the follow-on task to analyze the motor testing data to derive the parameters needed to develop a performance models for the single-phase air-conditioning (SPAC) unit. To derive the performance model, PNNL researchers first used the motor voltage and frequency ramping test data to obtain the real (P) and reactive (Q) power versus voltage (V) and frequency (f) curves. Then, curve fitting was used to develop the P-V, Q-V, P-f, and Q-f relationships for motor running and stalling states. The resulting performance model ignores the dynamic response of the air-conditioning motor. Because the inertia of the air-conditioning motor is very small (H<0.05), the motor reaches from one steady state to another in a few cycles. So, the performance model is a fair representation of the motor behaviors in both running and stalling states.}, institution={Office of Scientific and Technical Information (OSTI)}, author={Lu, Ning and Xie, YuLong and Huang, Zhenyu}, year={2008}, month={Sep} } @book{lu_de mello_makarov_2008, place={Richland, Washington}, title={CAISO Generation Flexibility Attributes Study Interim Report - CAISO Generation Flexibility Attributes Study Interim Report - Random Forecast Error Generator}, number={PNWD-4030}, institution={Battelle—Pacific Northwest Division}, author={Lu, N. and De Mello, P. and Makarov, Y.V.}, year={2008} } @book{lu_taylor_jiang_xie_leung_correia_wong_mackey_paget_2008, title={Climate Change Impacts on Residential and Commercial Loads in the Western U.S. Grid}, url={http://dx.doi.org/10.2172/947481}, DOI={10.2172/947481}, abstractNote={This report presents a multi-disciplinary modeling approach to quickly quantify climate change impacts on energy consumption, peak load, and load composition of residential and commercial buildings. This research focuses on addressing the impact of temperature changes on the building cooling load in 10 major cities across the Western United States and Canada. Our results have shown that by the mid-century, building yearly energy consumption and peak load will increase in the Southwest. Moreover, the peak load months will spread out to not only the summer months but also spring and autumn months. The Pacific Northwest will experience more hot days in the summer months. The penetration of the air conditioning (a/c) system in this area is likely to increase significantly over the years. As a result, some locations in the Pacific Northwest may be shifted from winter peaking to summer peaking. Overall, the Western U.S. grid may see more simultaneous peaks across the North and South in summer months. Increased cooling load will result in a significant increase in the motor load, which consumes more reactive power and requires stronger voltage support from the grid. This study suggests an increasing need for the industry to implement new technology to increase the efficiency of temperature-sensitive loads and apply proper protection and control to prevent possible adverse impacts of a/c motor loads.}, institution={Office of Scientific and Technical Information (OSTI)}, author={Lu, Ning and Taylor, Zachary T. and Jiang, Wei and Xie, YuLong and Leung, Lai R. and Correia, James and Wong, Pak C. and Mackey, Patrick S. and Paget, Maria L.}, year={2008}, month={Sep} } @book{lu_yang_huang_2008, place={Richland, Washington}, title={Evaluation of Southern California Edison Air-Conditioner Stalling Solutions}, number={PNNL-17686}, institution={CEC/LMTF Load Research Program, Pacific Northwest National Laboratory}, author={Lu, N. and Yang, B. and Huang, Z.}, year={2008} } @inbook{lu_xie_huang_puyleart_yang_ieee_2008, title={Load Component Database of Household Appliances and Small Office Equipment}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000264403802264&KeyUID=WOS:000264403802264}, booktitle={2008 Ieee Power & Energy Society General Meeting, Vols 1-11}, author={Lu, Ning and Xie, Yulong and Huang, Zhenyu and Puyleart, Francis and Yang, Steve and Ieee}, year={2008}, pages={4656-+} } @book{lu_qiao_2007, place={Richland, WA}, title={Composite load model evaluation}, number={PNNL-16916}, institution={Pacific Northwest National Laboratory}, author={Lu, N. and Qiao, A.}, year={2007} } @inbook{harnmerstrom_zhou_lu_ieee_2007, title={Controller design of power quality-improving appliances}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000252375202020&KeyUID=WOS:000252375202020}, booktitle={2007 Ieee Power Electronics Specialists Conference, Vols 1-6}, author={Harnmerstrom, D. J. and Zhou, N. and Lu, N. and Ieee}, year={2007}, pages={1164–1169} } @inbook{lu_li_sun_khaleel_ieee_2007, title={Dynamic modeling in solid-oxide fuel cells controller design}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000251345400048&KeyUID=WOS:000251345400048}, booktitle={2007 Ieee Power Engineering Society General Meeting, Vols 1-10}, author={Lu, N. and Li, Q. and Sun, X. and Khaleel, M. A. and Ieee}, year={2007}, pages={234-+} } @book{chassin_lu_2007, place={Richland, Washington}, title={Load Composition Data}, number={PNNL-SA-57496}, institution={Pacific Northwest National Laboratory}, author={Chassin, D.P. and Lu, N.}, year={2007} } @book{huang_lesieutre_yang_ellis_meklin_wong_gaikwad_brooks_hammerstrom_phillips_et al._2007, title={Load Monitoring CEC/LMTF Load Research Program}, url={http://dx.doi.org/10.2172/937047}, DOI={10.2172/937047}, abstractNote={This white paper addresses the needs, options, current practices of load monitoring. Recommendations on load monitoring applications and future directions are also presented.}, institution={Office of Scientific and Technical Information (OSTI)}, author={Huang, Zhenyu and Lesieutre, B. and Yang, Steve and Ellis, A. and Meklin, A. and Wong, B. and Gaikwad, A. and Brooks, D. and Hammerstrom, Donald J. and Phillips, John and et al.}, year={2007}, month={Nov} } @inproceedings{lu_sun_khaleel_2006, title={A Modeling and Experimental Framework for Controls for Fuel Cells}, booktitle={Proc. of the 2006 Second International Symposium on Communications, Control and Signal Processing}, author={Lu, N. and Sun, X. and Khaleel, M.A.}, year={2006} } @book{hammerstrom_guttromson_lu_boyd_trudnowski_chassin_bonebrake_shaw_2006, place={Richland, Washington}, title={Beacon Detection in Electric Distribution Systems For Grid Friendly Operations}, number={PNNL-15854}, institution={Pacific Northwest National Laboratory}, author={Hammerstrom, D.J. and Guttromson, R.T. and Lu, N. and Boyd, P.A. and Trudnowski, D. and Chassin, D.P. and Bonebrake, C.A. and Shaw, J.M.}, year={2006} } @book{lu_hammerstrom_ieee_2006, title={Design considerations for frequency responsive Grid Friendly (TM) appliances}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000244311700132&KeyUID=WOS:000244311700132}, journal={2005/2006 Ieee/Pes Transmission & Distribution Conference & Exposition, Vols 1-3}, author={Lu, Ning and Hammerstrom, Donald J. and Ieee}, year={2006}, pages={647-+} } @inbook{katipamula_lu_ashrae_2006, title={Evaluation of residential HVAC control strategies for demand response programs}, volume={112}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000238183500050&KeyUID=WOS:000238183500050}, booktitle={Ashrae Transactions 2006, Vol 112, Pt 1}, author={Katipamula, Srinivas and Lu, Ning and Ashrae}, year={2006}, pages={535-+} } @book{lu_nguyen_ieee_2006, title={Grid friendly (TM) appliances - Load-side solution for congestion management}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000244311700252&KeyUID=WOS:000244311700252}, journal={2005/2006 Ieee/Pes Transmission & Distribution Conference & Exposition, Vols 1-3}, author={Lu, Ning and Nguyen, Tony and Ieee}, year={2006}, pages={1269-+} } @article{lu_li_sun_khaleel_2006, title={The modeling of a standalone solid-oxide fuel cell auxiliary power unit}, volume={161}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000241781200028&KeyUID=WOS:000241781200028}, DOI={10.1016/j.jpowsour.2006.05.009}, abstractNote={In this research, a Simulink model of a standalone vehicular solid-oxide fuel cell (SOFC) auxiliary power unit (APU) is developed. The SOFC APU model consists of three major components: a controller model; a power electronics system model; and an SOFC plant model, including an SOFC stack module, two heat exchanger modules, and a combustor module. This paper discusses the development of the nonlinear dynamic models for the SOFC stacks, the heat exchangers and the combustors. When coupling with a controller model and a power electronic circuit model, the developed SOFC plant model is able to model the thermal dynamics and the electrochemical dynamics inside the SOFC APU components, as well as the transient responses to the electric loading changes. It has been shown that having such a model for the SOFC APU will help design engineers to adjust design parameters to optimize the performance. The modeling results of the SOFC APU heat-up stage and the output voltage response to a sudden load change are presented in this paper. The fuel flow regulation based on fuel utilization is also briefly discussed.}, number={2}, journal={Journal of Power Sources}, author={Lu, N. and Li, Q. and Sun, X. and Khaleel, M. A.}, year={2006}, pages={938–948} } @inbook{lu_katipamula_ieee_2005, title={Control strategies of thermostatically controlled appliances in a competitive electricity market}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000232799400031&KeyUID=WOS:000232799400031}, booktitle={2005 Ieee Power Engineering Society General Meeting, Vols, 1-3}, author={Lu, N. and Katipamula, S. and Ieee}, year={2005}, pages={202–207} } @book{khaleel_sun_koeppel_nguyen_lu_2005, place={Richland, Washington}, title={Modeling and Control of an SOFC APU}, number={PNNL-15396}, institution={Pacific Northwest National Laboratory}, author={Khaleel, M.A. and Sun, X. and Koeppel, B.J. and Nguyen, B.N. and Lu, N.}, year={2005} } @article{lu_chassin_widergren_2005, title={Modeling uncertainties in aggregated thermostatically controlled loads using a state queueing model}, volume={20}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000228778800025&KeyUID=WOS:000228778800025}, DOI={10.1109/tpwrs.2005.846072}, abstractNote={To study the impacts of price responsive demand on the electric power system requires better load models. This paper discusses the modeling of uncertainties in aggregated thermostatically controlled loads using a state queueing (SQ) model. The cycling times of thermostatically controlled appliances (TCAs) vary with the TCA types and sizes, as well as the ambient temperatures. The random consumption of consumers, which shortens or prolongs a specific TCA cycling period, introduces another degree of uncertainty. By modifying the state transition matrix, these random factors can be taken into account in a discrete SQ model. The impacts of considering load diversity in the SQ model while simulating TCA setpoint response are also studied.}, number={2}, journal={Ieee Transactions on Power Systems}, author={Lu, N. and Chassin, D. P. and Widergren, S. E.}, year={2005}, pages={725–733} } @inbook{lu_chassin_widergren_ieee_2005, title={Modeling uncertainties in aggregated thermostatically controlled loads using a state queueing model}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000232799401061&KeyUID=WOS:000232799401061}, booktitle={2005 Ieee Power Engineering Society General Meeting, Vols, 1-3}, author={Lu, N. and Chassin, D. P. and Widergren, S. E. and Ieee}, year={2005}, pages={1336} } @inbook{lu_taylor_chassin_guttromson_studham_ieee_2005, title={Parallel computing environments and methods for power distribution system simulation}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000232799400033&KeyUID=WOS:000232799400033}, booktitle={2005 Ieee Power Engineering Society General Meeting, Vols, 1-3}, author={Lu, N. and Taylor, Z. T. and Chassin, D. P. and Guttromson, R. and Studham, S. and Ieee}, year={2005}, pages={215–220} } @article{lu_chassin_2004, title={A state-queueing model of thermostatically controlled appliances}, volume={19}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000222975800050&KeyUID=WOS:000222975800050}, DOI={10.1109/tpwrs.2004.831700}, abstractNote={This paper develops a state-queueing model to analyze the price response of aggregated loads consisting of thermostatically controlled appliances (TCAs). Assuming a perfectly diversified load before the price response, we show that TCA setpoint changes in response to the market price will result in a redistribution of TCAs in on/off states and therefore change the probabilities for a unit to reside in each state. A randomly distributed load can be partially synchronized and the aggregated diversity lost. The loss of the load diversity can then create unexpected dynamics in the aggregated load profile. Raising issues such as restoring load diversity and damping the peak loads are also addressed in this paper.}, number={3}, journal={Ieee Transactions on Power Systems}, author={Lu, N. and Chassin, D. P.}, year={2004}, pages={1666–1673} } @book{chassin_malard_posse_gangopadhyaya_lu_katipamula_mallow_2004, title={Modeling Power Systems as Complex Adaptive Systems}, url={http://dx.doi.org/10.2172/877087}, DOI={10.2172/877087}, abstractNote={Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today's most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This report explores the state-of-the-art physical analogs for understanding the behavior of some econophysical systems and deriving stable and robust control strategies for using them. We review and discuss applications of some analytic methods based on a thermodynamic metaphor, according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood. We apply these methods to the question of how power markets can be expected to behave under a variety of conditions.}, institution={Office of Scientific and Technical Information (OSTI)}, author={Chassin, David P. and Malard, Joel M. and Posse, Christian and Gangopadhyaya, Asim and Lu, Ning and Katipamula, Srinivas and Mallow, J V.}, year={2004}, month={Dec} } @article{lu_chow_desrochers_2004, title={Pumped-Storage Hydro-Turbine Bidding Strategies in a Competitive Electricity Market}, volume={19}, ISSN={0885-8950}, url={http://dx.doi.org/10.1109/tpwrs.2004.825911}, DOI={10.1109/tpwrs.2004.825911}, abstractNote={This paper develops optimal pumped-storage unit bidding strategies in a competitive electricity market. Starting from a weekly forecasted market clearing price curve, an algorithm to maximize the profit of a pumped-storage unit considering reserve bids is developed. A comparison between the optimal bidding strategy and a fixed-schedule weekly generating and pumping strategy is provided.}, number={2}, journal={IEEE Transactions on Power Systems}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Lu, N. and Chow, J.H. and Desrochers, A.A.}, year={2004}, month={May}, pages={834–841} } @inproceedings{lu_chow_desrochers_2004, title={Pumped-storage hydro-turbine bidding strategies in a competitive electricity market}, ISBN={0780379896}, url={http://dx.doi.org/10.1109/pes.2003.1270415}, DOI={10.1109/pes.2003.1270415}, abstractNote={This paper develops optimal pump-hydro unit bidding strategies in a competitive electricity market. Starting from a weekly forecasted market clearing price (MCP) curve, an algorithm to maximize the profit of a pump-hydro unit considering reserve bids is developed. A comparison between the optimal bidding strategy and a fixed-schedule weekly generating and pumping strategy is provided.}, booktitle={2003 IEEE Power Engineering Society General Meeting (IEEE Cat. No.03CH37491)}, publisher={IEEE}, author={Lu, N. and Chow, J.H. and Desrochers, A.A.}, year={2004}, month={Jun} } @book{lu_chassin_widergren_ieee_2004, title={Simulating price responsive distributed resources}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000226108300254&KeyUID=WOS:000226108300254}, journal={2004 Ieee Pes Power Systems Conference & Exposition, Vols 1 - 3}, author={Lu, N. and Chassin, D. P. and Widergren, S. E. and Ieee}, year={2004}, pages={1538–1543} } @inproceedings{lu_chow_desrochers_2003, title={A multi-layer Petri net model for deregulated electric power systems}, ISBN={0780372980}, url={http://dx.doi.org/10.1109/acc.2002.1024858}, DOI={10.1109/acc.2002.1024858}, abstractNote={This paper proposes a hybrid multilayer Petri net model for electric power systems. The base layer is the physical layer, which represents the physical flow in a power system. On top of it are information layers to model information flows, which schedule the physical flow via discrete tokens. In between, there is an interface layer coded as programs and functioning as a control agent. An extension of continuous Petri nets, called a variable arc weighting Petri net (VAWPN), is introduced to simulate the physical layer, in which vector tokens are used to match the information flows to the physical flows. The operation of a VAWPN is presented. A three-zone example of a power system dispatch model is used to illustrate the concepts.}, booktitle={Proceedings of the 2002 American Control Conference (IEEE Cat. No.CH37301)}, publisher={American Automatic Control Council}, author={Lu, Ning and Chow, J.H. and Desrochers, A.A.}, year={2003}, month={Jun} } @book{lu_warwick_steese_arey_dagle_jarrell_weimar_2003, place={Florida}, title={Security Benefits of Renewable Generation: A Case Study}, institution={Prepared for U.S. Air Force Civil Engineering Support Agency Headquarters, Tyndall Air Force Base}, author={Lu, N. and Warwick, W.M. and Steese, J.G.De and Arey, S.J. and Dagle, J.E. and Jarrell, D.B. and Weimar, M.R.}, year={2003} } @inproceedings{lu_chow_desrochers_2002, title={Generator Bidding Strategies in a Competitive Deregulated Market Accounting for Availability and Bid Segments}, booktitle={Proc. of VIII Symposium of Specialists in Electric Operational and Expansion Planning}, author={Lu, N. and Chow, J.H. and Desrochers, A.A.}, year={2002} }