@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{crawford_baran_2024, title={Topology Error Monitoring Using Bad Data Detection Methods}, url={https://doi.org/10.1109/TIA.2023.3321029}, DOI={10.1109/TIA.2023.3321029}, abstractNote={For real-time monitoring of distribution systems, distribution system state estimation (DSSE) methods have been developed. For accurate DSSE results, an accurate system model is needed. However, topology of a distribution network changes due to various reasons and some changes may not be monitored or known to the control center. This leads to an incorrect model used for the DSSE and thus causes incorrect estimation results. The main contributions of this article includes development of a topology monitoring scheme using bad data detection (BDD) methods in the presence of the most common topology errors in practice, including capacitor bank failure and load balancing. Additionally, common measurement schemes are investigated to determine how a measurement scheme can be used in order to improve topology error detection. Test results using a sample IEEE distribution feeder have been provided to illustrate the the effectiveness of the proposed scheme.}, journal={IEEE Transactions on Industry Applications}, author={Crawford, Ken and Baran, Mesut E.}, year={2024}, month={Jan} }
 @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{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{chen_baran_2023, title={Robust Controller for Community Microgrids for Stability Improvement in Islanded Mode}, volume={38}, ISSN={["1558-0679"]}, DOI={10.1109/TPWRS.2022.3192459}, abstractNote={Many utilities are developing microgrids to improve power reliability and grid resiliency for customers. One critical challenge in microgrid design is maintaining system stability with changing operating conditions in the microgrid. The technical and contractual constraints of accessibility and controllability to customer-owned resources limit available control options. This paper details a single-phase community microgrid model and illustrates the stability challenges. It further proposes adopting an optimal controller using predictive current control (PCC) and robust control mu-synthesis to improve microgrid stability in islanded operating mode. Incorporating the mu-synthesis in the controller design assures the microgrid's robust stability. The proposed method facilitates the incorporation of main uncertainties in the microgrid: change in resources, uncertainties in their modeling, and load variation. The proposed method overcomes the constraints and does not impact the customer's resources normal operation. Furthermore, the controller has a simple structure and is easy to implement. The simulation results validate that the designed controller can maintain the system stability and achieve optimal performance against various changes in the microgrid. This paper presents a practical solution to the challenges utilities are facing in microgrid development.}, number={3}, journal={IEEE TRANSACTIONS ON POWER SYSTEMS}, author={Chen, Ke and Baran, Mesut}, year={2023}, month={May}, pages={2472–2484} }
 @article{dsouza_muthukaruppan_yu_baran_lukic_vukojevic_2022, title={Assessment of Anti-Islanding Schemes on a Distribution System with High DER Penetration and Dynamic VAR Compensators}, ISSN={["2329-5759"]}, DOI={10.1109/PEDG54999.2022.9923268}, abstractNote={The recently introduced power-electronics-based dynamic VAR compensator (DVC) offers an effective solution in mitigating the impacts that high penetration distributed energy resources (DERs) have on distribution systems. One of the concerns about adopting these devices is their impact on distribution system protection, especially islanding detection. This paper proposes a hardware-in-loop (HIL) test-bed based approach to investigate the performance of islanding detection schemes on a distribution feeder. This approach facilitates the assessment of protection system performance under more realistic conditions by emulating actual devices and a distribution system. The results are based on an actual case study that is outlined to show the effectiveness of existing passive anti-islanding schemes and assess the impact of a DVC on islanding detection.}, journal={2022 IEEE 13TH INTERNATIONAL SYMPOSIUM ON POWER ELECTRONICS FOR DISTRIBUTED GENERATION SYSTEMS (PEDG)}, author={DSouza, Keith and Muthukaruppan, Valliappan and Yu, Hui and Baran, Mesut and Lukic, Srdjan and Vukojevic, Aleksandar}, year={2022} }
 @article{dsouza_baran_vukojevic_2022, title={Maximizing the Benefits of Dynamic VAR Compensators on Distribution Systems with High Penetration PV}, ISSN={["2329-5759"]}, DOI={10.1109/PEDG54999.2022.9923214}, abstractNote={High penetration of solar photovotaic systems (PVs) in a distribution system can impact its operation considerably, causing issues like voltage violations, voltage flicker, increase in system losses and excessive regulator operations. Recently, power- electronics-based Dynamic VAR Compensators (DVCs) have been developed as an effective solution to mitigate these issues caused by PVs. In order to assess the benefits of DVCs (and other such devices), this paper first introduces metrics to quantify the main benefits a DVC offers, such as a reduction in tap operation, voltage variation, voltage flicker, etc. This paper also proposes a methodology to properly place and dispatch the DVC to maximize these benefits. The case study presented illustrates the effectiveness of the proposed methodology and highlights the achievable benefits. The results indicate that it is possible to obtain multiple benefits from a DVC in distribution systems with high penetration PV.}, journal={2022 IEEE 13TH INTERNATIONAL SYMPOSIUM ON POWER ELECTRONICS FOR DISTRIBUTED GENERATION SYSTEMS (PEDG)}, author={DSouza, Keith and Baran, Mesut and Vukojevic, Aleksandar}, year={2022} }
 @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{wang_dsouza_tang_baran_2021, title={Assessing the Impact of High Penetration PV on the Power Transformer Loss of Life on a Distribution System}, ISSN={["2165-4816"]}, DOI={10.1109/ISGTEUROPE52324.2021.9640091}, abstractNote={Increasing photovoltaic (PV) systems on a distribution system impact the operation and lifetime of its components. One of the key components to be impacted is the power transformer at the substation. In this paper, we aim to evaluate the impact of high penetration PV on the lifetime of the substation power transformer. At moderate levels of PV penetration, the loading on the substation transformer decreases, and therefore this will help to prolong the lifetime of the transformer. To estimate this expected benefit, a thermal model for the transformer is used to estimate its hot spot temperature as this temperature is the main factor affecting the degradation of the transformer under normal loading conditions. To illustrate the method, a case study is given. A 10-year period is considered for transformer loss of life evaluation, where practical load growth and PV penetration scenarios are considered. The simulation is carried out on a 15 MVA transformer in the IEEE 123 bus system. Simulation results show that PV penetrations below 100% indeed prolong the transformer lifetime. However, the saved transformer lifetime is not considerable compared to the total transformer lifespan.}, journal={2021 IEEE PES INNOVATIVE SMART GRID TECHNOLOGY EUROPE (ISGT EUROPE 2021)}, author={Wang, Xiaochu and DSouza, Keith and Tang, Wenyuan and Baran, Mesut}, year={2021}, pages={323–327} }
 @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{chen_baran_2021, title={Impedance-Based Stability Analysis of a Single-Phase Community Microgrid in Islanded Mode}, ISSN={["2167-9665"]}, DOI={10.1109/ISGT49243.2021.9372204}, abstractNote={When a microgrid operates in islanded mode, stability becomes an issue, especially as the system configuration changes over time. This calls for a systematic modeling approach to study the stability of microgrid in islanded mode. In this paper, the impedance-based stability analysis is applied to assess the stability of a single-phase community microgrid in islanded mode. A new method of impedance modeling of single-phase inverter using the state-space model based approach is proposed. This method is successfully adopted in the case study to assess the microgrid stability under different conditions. The case study results suggest the need for more robust DER interface design and DER control to maintain the microgrid stability.}, journal={2021 IEEE POWER & ENERGY SOCIETY INNOVATIVE SMART GRID TECHNOLOGIES CONFERENCE (ISGT)}, author={Chen, Ke and Baran, Mesut}, year={2021} }
 @article{crawford_baran_2021, title={Improving Topology Error Detection with Distribution System State Estimation}, DOI={10.1109/TPEC54980.2022.9750804}, abstractNote={For real-time monitoring of distribution systems, distribution system state estimation (DSSE) methods have been developed. For accurate DSSE results, an accurate system model is needed. However, topology of a distribution network changes due to various reasons and some changes may not be monitored or known to the control center. This leads to an incorrect model used for the DSSE and thus causes incorrect estimation results. The contributions of this paper include an investigation on the capability of DSSE for bad data detection (BDD) in the presence of most common topology errors in practice, including capacitor bank failure and load balancing. Additionally, common measurement schemes are investigated to determine how a measurement scheme can be improved in order to improve topology error detection. Test results using a sample IEEE distribution feeder has been provided to illustrate the challenges associated with topology error detection using DSSE.}, journal={2022 IEEE TEXAS POWER AND ENERGY CONFERENCE (TPEC)}, author={Crawford, Ken and Baran, Mesut}, year={2021}, pages={79–84} }
 @article{cakir_baran_2021, title={Performance Assessment of Current Based Distribution System State Estimator}, DOI={10.1109/TPEC54980.2022.9750793}, abstractNote={State estimation methods need to be tailored for real-time monitoring at distribution level to address the computational burden. One of the promising approaches converts the measurements to equivalent current measurements. This paper focuses on a comprehensive assessment of the performance of this method. The metrics adopted aims to assess the main performance issues of bias, consistency, and quality. This paper also examines the dependency of the method's performance on the measurements available for estimation. Test results on a sample test feeder have also been provided to illustrate the importance of the proposed performance assessment approach, as the results show that the performance metrics used provide valuable insights about the limitations of the use of the equivalent current injections when there is only a limited number of measurements available at distribution level.}, journal={2022 IEEE TEXAS POWER AND ENERGY CONFERENCE (TPEC)}, author={Cakir, Gokhan and Baran, Mesut}, year={2021}, pages={61–66} }
 @article{dsouza_wang_cakir_baran_zhao_2021, title={Power Electronics Assisted Voltage Regulator: An Effective Solution for Mitigating Voltage Variations Caused by High Penetration PV on a Distribution System}, ISSN={["2329-5759"]}, DOI={10.1109/PEDG51384.2021.9494246}, abstractNote={The ever-increasing levels of distributed energy resources (DERs), especially solar photovoltaics (PV) tend to detrimentally affect the operation of the distribution systems on which they are installed, causing issues like voltage violations, excessive voltage regulator operations, voltage flicker, etc. Recent improvements in power electronics have led to an increase in the proliferation of power electronics based voltage regulators that are capable of fast voltage compensation. However, being a recent addition, very few studies exist that quantify the benefits of such devices on a distribution system. This work uses a case study to quantify the main benefits of a power electronics assisted voltage regulator (PEVR) in mitigating the impacts of high penetration PV using a supervisory control scheme for the PEVR. This study considers high resolution (1 second) PV and load profiles to capture the accurate operation of the step voltage regulator (SVR) and PEVR. The results from this case study highlight the effectiveness of a PEVR in mitigating excessive voltage variation and tap operations due to high penetration PV. The results also illustrate the trade-off between converter capacity and benefits.}, journal={2021 IEEE 12TH INTERNATIONAL SYMPOSIUM ON POWER ELECTRONICS FOR DISTRIBUTED GENERATION SYSTEMS (PEDG)}, author={DSouza, Keith and Wang, Yafeng and Cakir, Gokhan and Baran, Mesut and Zhao, Tiefu}, year={2021} }
 @article{li_baran_2020, title={A Novel Frequency Support Control Method for PV Plants Using Tracking LQR}, volume={11}, ISSN={["1949-3037"]}, DOI={10.1109/TSTE.2019.2953684}, abstractNote={Growing level of Photovoltaic (PV) generation challenges the conventional generation control in power systems, as the current PV systems do not possess inertia or governor system. However, a supervisory control can be adopted for such PV systems to provide frequency support. In this article, a novel controller for large-scale PV plants is proposed for this purpose. Different than other approaches which only focus on emulating droop and inertial response of local PV, the proposed approach uses a tracking linear quadratic regulator (LQR) based controller to help the system frequency effectively track that of a designed reference system with given inertia and droop constants. To design the LQR, an unknown input observer (UIO) is adopted to estimate the system states, as well as the unknown disturbance. We also introduce a small-signal PV system model which is suitable for designing frequency support controls. The model is validated against the detailed nonlinear PV system model, and the effectiveness of the proposed controller is demonstrated using a standard test system. Test results also show that the proposed method achieves the desired frequency response more effectively than the alternative method from literature, while the later method is liable to over-compensation of frequency response at the price of requiring more power reserve in PV.}, number={4}, journal={IEEE TRANSACTIONS ON SUSTAINABLE ENERGY}, author={Li, Qinmiao and Baran, Mesut E.}, year={2020}, month={Oct}, pages={2263–2273} }
 @article{al kez_foley_mcilwaine_morrow_hayes_zehir_mehigan_papari_edrington_baran_2020, title={A critical evaluation of grid stability and codes, energy storage and smart loads in power systems with wind generation}, volume={205}, ISSN={["1873-6785"]}, DOI={10.1016/j.energy.2020.117671}, abstractNote={Existing power systems are facing new challenges in maintaining the security of the power system as the penetration of variable renewable energy technologies, such as variable speed wind turbines, increase. System non-synchronous generation replaces conventional generators as penetration of renewable generation increases. This affects system rotational inertia and limits the number of online thermal generators that can provide frequency stability services and system-wide areas voltage stability. This evolution has resulted in some changes to existing grid codes and new ancillary services. Furthermore, it could provide opportunities to address the security of the system utilizing modern smart technologies, e.g. smart loads, heat pumps and electric vehicles. The aim of this paper is to evaluate the impacts of large-scale renewable power generation on power system dynamics from the perspective of the power system operator. It focuses on the grid codes implications and challenges specifically. Synthetic inertia response opportunities from smart loads, electric vehicles and energy storage technologies and dispatching wind farms during frequency excursions are analyzed and thoroughly discussed. The key finding is that rethinking in the development of grid code requirements and market mechanisms are needed if a power system based on 100% power electronic renewable generation is to be achieved. This type of power system would need a range of technologies to provide the types of ancillary (i.e. system) services required, as none of the technologies alone can tackle all the challenges presented.}, journal={ENERGY}, author={Al Kez, Dlzar and Foley, Aoife M. and McIlwaine, Neil and Morrow, D. John and Hayes, Barry P. and Zehir, M. Alparslan and Mehigan, Laura and Papari, Behnaz and Edrington, Chris S. and Baran, Mesut}, year={2020}, month={Aug} }
 @article{ozdemir_baran_2020, title={A new method for Volt-Var optimization with conservation voltage reduction on distribution systems}, volume={102}, ISSN={["1432-0487"]}, DOI={10.1007/s00202-020-00945-4}, number={1}, journal={ELECTRICAL ENGINEERING}, author={Ozdemir, Gulcihan and Baran, Mesut}, year={2020}, month={Mar}, pages={493–502} }
 @article{chen_xiao_baran_wang_2019, title={Online contingency analysis method for multi-terminal DC distribution networks with renewable resources}, volume={13}, ISSN={["1751-8695"]}, DOI={10.1049/iet-gtd.2018.5318}, abstractNote={In this study, an interval arithmetic-based method has been proposed for contingency analysis of line outage in DC distribution networks. This method incorporates the uncertainties in source/load which become considerable in the system with increasing renewable generations and time-varying loads. Two-stage contingency analysis approach is adopted in this method. For the first stage of contingency screening, a contingency filter has been developed based on interval matrix norm to quickly estimate the bounds of operating state in the post-outage period. For the second stage of detailed analysis to the selected contingencies, the interval analytical model is first transformed into a non-linear programming-based equivalent model. To solve this model accurately and efficiently, successive linear programming and reformulation-linearisation techniques are employed. The proposed method is benchmarked against Monte Carlo simulations and line outage distribution factor-based method.}, number={8}, journal={IET GENERATION TRANSMISSION & DISTRIBUTION}, author={Chen, Pengwei and Xiao, Xiangning and Baran, Mesut and Wang, Xiaochu}, year={2019}, month={Apr}, pages={1305–1314} }
 @article{moon_baran_2018, title={Economic analysis of a residential PV system from the timing perspective: A real option model}, volume={125}, ISSN={["0960-1481"]}, DOI={10.1016/j.renene.2018.02.138}, abstractNote={This paper proposes a new model for determining optimal investment time for residential photovoltaic (PV) power systems. The model explicitly incorporates the cost uncertainty of the PV system and a resident's option to defer investment, using a real option model. The paper provides theoretical analysis as well as case studies. Using the real option model, we show that the optimal investment threshold decreases in case of volatility increase, mean-drift decrease and benefit decrease. A sensitivity analysis using different PV sizes illustrates that the optimal waiting time for substantial PV diffusion to smaller PV systems is longer than that of larger systems. The paper also investigates the expected investment times in the United States, Germany, Japan, and Korea and shows that all countries except Germany need to wait to invest. Moreover, a comparison study to the net present value (NPV) method demonstrates that PV system investment can be additionally delayed by 5.76–11.01 years.}, journal={RENEWABLE ENERGY}, author={Moon, Yongma and Baran, Mesut}, year={2018}, month={Sep}, pages={783–795} }
 @inproceedings{sun_thomas_singh_li_baran_lubkeman_decarolis_queiroz_white_watts_et al._2017, title={Cost-benefit assessment challenges for a smart distribution system: A case study}, volume={2018-January}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85046337981&partnerID=MN8TOARS}, DOI={10.1109/pesgm.2017.8274167}, abstractNote={The FREEDM system is a technology for a smarter and resilient distribution system that facilitates a higher level of distributed energy resource (DER) integration by offering effective voltage regulation, reactive power compensation and real time monitoring and control. This paper provides a framework for conducting a cost-benefit analysis for such a smart distribution system. The method first identifies the benefits, and then quantifies and monetizes them. OpenDSS time-series based power flow simulation is used to quantify the benefits accurately. The costs associated with the new components of the system are estimated based on prototype units. A cost-benefit analysis is adopted to identify the scenarios where employing such a system by a utility becomes economically attractive.}, booktitle={2017 ieee power & energy society general meeting}, author={Sun, L. S. and Thomas, J. and Singh, S. and Li, D. X. and Baran, M. and Lubkeman, David and DeCarolis, J. and Queiroz, A. R. and White, L. and Watts, S. and et al.}, year={2017}, pages={1–5} }
 @article{hooshyar_baran_firouzi_vanfretti_2017, title={PMU-assisted overcurrent protection for distribution feeders employing Solid State Transformers}, volume={10}, ISSN={["2352-4677"]}, DOI={10.1016/j.segan.2017.02.003}, abstractNote={Solid State Transformer (SST) has recently emerged as an approach to facilitate the integration of Distributed Energy Resources (DERs) at the distribution system level. However, SSTs impact the operation and coordination of protection relays as they will contribute to the fault current during a fault. This paper shows that the impact of SSTs on the overcurrent protection relays can be considerable. The paper proposes an enhancement to the traditional overcurrent scheme by exploiting embedded PMU functionality in SSTs and in feeder protective relays. Performance of the proposed scheme has been assessed through the use of hardware-in-the-loop simulation on a sample distribution feeder.}, journal={SUSTAINABLE ENERGY GRIDS & NETWORKS}, author={Hooshyar, H. and Baran, M. E. and Firouzi, S. R. and Vanfretti, L.}, year={2017}, month={Jun}, pages={26–34} }
 @inproceedings{singh_baran_2017, title={Protection of smart distribution systems with distributed energy resources and solid state transformers}, DOI={10.1109/pesgm.2017.8273791}, abstractNote={This paper focuses on the development of a protection scheme for a smart distribution system containing DERs (Distributed Energy Resources) and Solid State Transformers (SSTs). First, the paper describes the fault analysis that needs to be conducted on such systems. Then, a communication assisted protection scheme is proposed, in order to overcome the shortcomings observed in the conventional protection schemes.}, booktitle={2017 ieee power & energy society general meeting}, author={Singh, U. and Baran, Mesut}, year={2017} }
 @inproceedings{shi_shen_baran_2016, title={A decentralized volt/var optimization scheme for smart distribution systems}, DOI={10.1109/isgt.2016.7781176}, abstractNote={This paper considers the use of inverter interfaced distributed generators (DGs) for Volt/Var control in a distribution system with high penetration of DGs. A new decentralized Volt/Var Optimization (VVO) scheme is proposed to facilitate Volt/Var control for such a case. The proposed method is based on the Dantzig-Wolf decomposition and the paper shows that this approach facilitates dividing the distribution system into subareas where a local controller can be assigned. The effectiveness of DW-based decentralized VVO scheme is tested using the IEEE 34 node test feeder with high penetration of DGs.}, booktitle={2016 IEEE Power & Energy Society Innovative Smart Grid Technologies Conference (ISGT)}, author={Shi, Yue and Shen, Z. and Baran, Mesut}, year={2016} }
 @inproceedings{shi_baran_2016, title={An Automated model based fault locating method for distribution systems}, DOI={10.1109/tdc.2016.7519926}, abstractNote={This paper proposes an Event Screening method in order to facilitate the automated locating of permanent faults on a distribution feeder. The screening is needed as during a permanent fault, the fault current maybe interrupted by multiple operations of protection devices (PDs), and therefore determining the proper fault current for the model based fault locating method (FLM) becomes challenging. The Event Screening Method analyzes the all the events captured by the fault monitoring device (usually a PQ monitor) and determines the proper fault information needed by FLM. Test results for the improved FLM with Event Screening integrated are provided using a real distribution feeder. The results show that the Event Screening Method is able to accurately predict the operating sequence of PDs during a fault and that the improved FLM can accurately locate the faulted zone.}, booktitle={2016 IEEE/PES Transmission and Distribution Conference and Exposition (T&D)}, author={Shi, Yue and Baran, Mesut}, year={2016} }
 @inproceedings{emiroglu_ozdemir_baran_2016, title={Assessment of linear distribution feeder models used in optimization methods}, DOI={10.1109/isgt.2016.7781206}, abstractNote={Linear power flow models for distribution systems are widely used in optimization problems but their effectiveness has not been investigated thoroughly. This paper investigates the effectiveness of two commonly used linear feeder models used in optimization methods, in particular in Volt/Var optimization problems: linearized Backward-Forward based model and the Nodal based model. Tests performed on the three test systems - IEEE 13, 34 and 123 node test systems- illustrate the limitations of these linear models.}, booktitle={2016 IEEE Power & Energy Society Innovative Smart Grid Technologies Conference (ISGT)}, author={Emiroglu, S. and Ozdemir, G. and Baran, Mesut}, year={2016} }
 @inproceedings{singh_zamani_baran_2016, title={On-line load estimation for distribution automation using AMI data}, DOI={10.1109/pesgm.2016.7741806}, abstractNote={This paper presents a method to estimate the loads on a distribution feeder in real-time with limited real-time customer load data from AMI. The method consists of two modules: a load clustering module and a load modeling module. Load clustering helps to identify customer loads with similar profiles thereby helping to determine the subset of customers that need to be monitored in real-time. The load modelling module constructs statistical models for each load on the feeder. The module uses both the historical AMI data and the real-time AMI data from the selected customers in order to improve the performance of the model. Test results based on actual AMI data show the effectiveness of the method.}, booktitle={2016 ieee power and energy society general meeting (pesgm)}, author={Singh, U. and Zamani, V. and Baran, Mesut}, year={2016} }
 @inproceedings{ozdemir_emiroglu_baran_2016, title={Supervisory control for coordinating Volt/Var control devices on a distribution system}, DOI={10.1109/isgt.2016.7781162}, abstractNote={This paper proposes a computationally efficient method for supervisory control of Volt/Var control devices-voltage regulators and capacitor banks - on a distribution system. The method searches for the best control settings for these devices as the operating conditions change on the system in real-time. The objective of the supervisory control is that of a volt/var optimization - minimize the power losses on the distribution circuit while keeping the node voltages within the acceptable range. The method considers multiple voltage regulators and capacitor banks on a distribution feeder. The test results show the effectiveness of method in terms of providing the global optimal solution with fast computational speed.}, booktitle={2016 IEEE Power & Energy Society Innovative Smart Grid Technologies Conference (ISGT)}, author={Ozdemir, G. and Emiroglu, S. and Baran, Mesut}, year={2016} }
 @inproceedings{sbordone_huq_baran_2015, title={An experimental microgrid for laboratory activities}, DOI={10.1109/eeeic.2015.7165188}, abstractNote={This paper introduces development of a small scale microgrid which consists of a PV system, an energy storage device, and a load. The system is intended for conducting experiments to demonstrate and/or investigate different design and control issues related to microgrids. The system has also a data acquisition and power management component in order to facilitate monitoring and management of the system in different operating conditions. Hence, the system can be used for both education and research purposes. Two experiments have been provided to illustrate the flexibility of the proposed microgrid.}, booktitle={2015 IEEE 15th International Conference on Environment and Electrical Engineering (IEEE EEEIC 2015)}, author={Sbordone, D. A. and Huq, K. M. M. and Baran, Mesut}, year={2015}, pages={363–367} }
 @inproceedings{shi_baran_2015, title={Assessment of volt/var control schemes at power distribution level}, DOI={10.1109/naps.2015.7335108}, abstractNote={This paper proposes a general approach to assess the effectiveness of a Volt/Var control (VVC) scheme for a power distribution system. It first provides a comprehensive list of possible performance metrics for VVC. Then, a power flow based method is proposed to estimate the metrics considered. To illustrate the approach, a case study for a given VVC scheme on a test feeder with high PV penetration is also presented.}, booktitle={2015 north american power symposium (naps)}, author={Shi, Yue and Baran, Mesut}, year={2015} }
 @article{aminifar_meliopoulos_baran_romero-agueero_pahwa_grijalva_madani_giri_2015, title={Special Section on Monitoring, Visualization, and State Estimation for Distribution Systems}, volume={6}, ISSN={["1949-3061"]}, DOI={10.1109/tsg.2015.2436011}, abstractNote={Inherited from legacy technologies, electric distribution systems are aging infrastructures whose component failures have a significant role in customer electricity interruptions. Low visibility and controllability of the distribution grid are a common practice today across the globe. In this circumstance, elements of the distribution grid including overhead distribution lines, underground cables, breakers, sectionalizers, etc. are being operated with very limited real-time data acquisition and virtually no remote control capability. The majority of failures are not detected by system operators unless interrupted customers notify them by phone. Very often (and particularly in municipal areas with underground networks), a distribution system is scattered across a large (and cumbersome) geographical region. Therefore, fault location and service restoration by nature is a difficult and prolonged process. Most of the associated tasks such as restoration are manually implemented, which necessitates dispatching field crew to the affected regions. The lack of controllability of the distribution system, specifically, related to balancing loads with available generation, impedes islanded operation of distribution system at the event of main grid failure. For example, while transmission systems have generator inertia and governor controls which stabilize frequency during emergencies, distribution systems do not have such automated actions. As a result, during emergencies, various distributed energy resources (DERs) that might be available are most likely switched off instead of serving some portions of the affected customers.}, number={4}, journal={IEEE TRANSACTIONS ON SMART GRID}, author={Aminifar, Farrokh and Meliopoulos, Sakis and Baran, Mesut and Romero-Agueero, Julio and Pahwa, Anil and Grijalva, Santiago and Madani, Vahid and Giri, Jay}, year={2015}, month={Jul}, pages={1999–2001} }
 @article{baran_carpenter_borbye_lubkeman_ligett_covington_2014, title={A New Professional Science Master Program for Electric Power Systems Engineering}, volume={29}, ISSN={0885-8950 1558-0679}, url={http://dx.doi.org/10.1109/tpwrs.2014.2316290}, DOI={10.1109/tpwrs.2014.2316290}, abstractNote={This paper proposes to adopt the emerging Professional Science Master (PSM) program as a model for enriching power engineering education. PSM programs provide comprehensive training in an academic and technical specialty along with the appropriate professional skills needed for a professional career. The paper outlines the new PSM program-MS in Electric Power Systems Engineering. The program encompasses engineering, management, and other professional skills needed for a successful career in the power engineering industry, and includes both in-depth core power engineering topics as wells as new cross-disciplinary technical topics relevant to the clean-energy Smart Grid.}, number={4}, journal={IEEE Transactions on Power Systems}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Baran, Mesut E. and Carpenter, Pam Page and Borbye, Lisbeth and Lubkeman, David L. and Ligett, Michael and Covington, David H.}, year={2014}, month={Jul}, pages={1903–1910} }
 @inproceedings{baran_padmanabhan_chouhan_yuan_smith_mayfield_2014, title={A model based fault locating method for distribution systems}, DOI={10.1109/pesgm.2014.6939019}, abstractNote={This paper presents a Fault Locating Method (FLM) which uses the current waveforms from Power Quality (PQ) Monitors located on a distribution feeder to determine the location of a permanent fault on the feeder. The method is model based in that it uses a detailed feeder model to estimate the fault currents and compares it with the data obtained from PQ monitors. Test results on the proposed FLM have been provided for two different distribution feeders.}, booktitle={2014 ieee pes general meeting - conference & exposition}, author={Baran, Mesut and Padmanabhan, A. and Chouhan, S. and Yuan, X. Y. and Smith, J. and Mayfield, H.}, year={2014} }
 @article{hooshyar_baran_2013, title={Fault Analysis on Distribution Feeders With High Penetration of PV Systems}, volume={28}, ISSN={["1558-0679"]}, DOI={10.1109/tpwrs.2012.2227842}, abstractNote={Fault current profile on a PV-dominated distribution feeder is rather different than a conventional feeder. To estimate the fault current profile on such a feeder, the paper proposes a new method which extends the capability of conventional short-circuit analysis method. The paper also shows that this time-varying fault current profile makes it also more difficult to estimate the time it will take for an overcurrent relay/device to interrupt such a fault current. The paper proposes a method for estimation of this operating time also. Performance of the proposed methods has been assessed by simulations on a sample distribution feeder.}, number={3}, journal={IEEE TRANSACTIONS ON POWER SYSTEMS}, author={Hooshyar, Hossein and Baran, Mesut E.}, year={2013}, month={Aug}, pages={2890–2896} }
 @inproceedings{shen_baran_2013, title={Gradient based centralized optimal volt/var control strategy for smart distribution system}, DOI={10.1109/isgt.2013.6497865}, abstractNote={With the development of enabling power electronic devices, such as the solid state transformer (SST) [1], the concept of a novel future renewable electric energy delivery and management system [2] is raised. The Future Renewable Electric Energy Delivery and Management (FREEDM) system is a smart distribution system that can accommodate distributed renewable energy, distributed energy storage devices, and plug-in hybrid electric vehicles (PHEVs), As the complexity of the power system increases, the need for a sophisticated power system operation and control method is becoming a critical issue. The new devices shouldn't disturb normal system operations, and the capabilities of these devices should help support the customer needs and enhance system performance. Therefore, this paper develops a centralized Volt/Var control strategy to minimize power system losses while maintaining voltage profiles within acceptable limits.}, booktitle={2013 IEEE PES Innovative Smart Grid Technologies (ISGT)}, author={Shen, Z. and Baran, Mesut}, year={2013} }
 @article{she_baran_she_2013, title={Multiobjective Control of PEM Fuel Cell System With Improved Durability}, volume={4}, ISSN={["1949-3029"]}, DOI={10.1109/tste.2012.2203324}, abstractNote={A critical design goal of a fuel-cell-based renewable energy system in a smart grid scenario is to enable high efficiency while extending durability. This is particularly emphasized when the fuel-cell system becomes widely used. Towards this goal, the effort in this research paper is to develop multiobjective controllers to simultaneously realize both output tracking and durability improvement. More specifically, two types of controller are developed. With assumptions of knowledge of system parameters, the first controller enables exponentially stability of the closed-loop system. Then, with practical considerations of robustness, an adaptive extension of the first controller is developed, which is capable of handling possible mismatch between real parameters and parameters obtained from the manufacturer or system identification methods. The performance and stability is theoretically guaranteed by a Lyapunov-based proof. Together with theoretical analysis, several scenarios are considered and tested via Matlab/simulink-based simulation.}, number={1}, journal={IEEE TRANSACTIONS ON SUSTAINABLE ENERGY}, author={She, Yun and Baran, Mesut E. and She, Xu}, year={2013}, month={Jan}, pages={127–135} }
 @inproceedings{huq_baran_lukic_nare_2012, title={An energy management system for a community energy storage system}, DOI={10.1109/ecce.2012.6342532}, abstractNote={This paper considers the operational issues related to community level micro-grids which uses PV systems as the main local power generation. To facilitate the operation of such systems, the paper investigates the use of local storage, and proposes an Energy Management System (EMS) for this purpose. The paper shows that the proposed EMS can address the main operational issues, such as reducing energy consumption during peak loading conditions and limiting excess reverse power flow back to the utility.}, booktitle={2012 IEEE Energy Conversion Congress and Exposition (ECCE)}, author={Huq, K. M. M. and Baran, Mesut and Lukic, Srdjan and Nare, O. E.}, year={2012}, pages={2759–2763} }
 @inproceedings{shen_wang_baran_2012, title={Optimal volt/var control strategy for distribution system with multiple voltage regulating devices}, DOI={10.1109/tdc.2012.6281479}, abstractNote={This paper studies the volt/var control strategy for smart distribution system by formulating and solving system optimization problems. In the study, solid state transformers (SST) are used for continuous var compensation, while voltage regulators (VR) are for voltage regulation. The objectives are to minimize total system power loss while maintaining voltages along the feeder within acceptable limits. A two step optimization volt/var control method for multiple, discrete/continuous mixed regulating device is introduced in this paper. Simulation results demonstrate that the proposed technique is able to achieve the objective efficiently.}, booktitle={2012 ieee pes transmission and distribution conference and exposition (t&d)}, author={Shen, Z. and Wang, Z. and Baran, Mesut}, year={2012} }
 @inproceedings{shen_liu_baran_2012, title={Power management strategies for the green hub}, DOI={10.1109/pesgm.2012.6345698}, abstractNote={In this study power management strategies for a novel distribution level microgrid which is being developed at FREEDM center - Green Hub- are investigated. The Green Hub is a 12 kV distribution circuit with high level PV penetration. A large scale dispatchable distributed energy storage device (DERD) has also been added to this system to provide the additional power that is needed during islanding conditions. The high level penetration of photovoltaic (PV) units potentially necessitates new controls for both islanded and grid-connected X operation modes and smooth transition between the two modes to enable the best utilization of the microgrid resources. In this paper, state-of-the-art power management strategies have been investigated for this purpose. The Green Hub has been simulated using simpower/simulink of MATLAB, and it is used to assess the performance of the centralized control scheme considered.}, booktitle={2012 IEEE Power and Energy Society General Meeting}, author={Shen, Z. and Liu, Z. N. and Baran, Mesut}, year={2012} }
 @inproceedings{baran_hooshyar_shen_gajda_huq_2011, title={Impact of high penetration residential PV systems on distribution systems}, DOI={10.1109/pes.2011.6039799}, abstractNote={This paper investigates the operation and protection issues on a distribution system with high penetration of residential PV systems. PV systems are smaller scale resources and therefore they have different impact on a distribution circuit than larger scale resources. The paper indeed considers a typical residential feeder and investigates PV system impacts on the system at different penetration levels. Simulations on this system show that the even the high penetration level PV systems can be accommodated as the impact on the system will not be severe.}, booktitle={2011 ieee power and energy society general meeting}, author={Baran, Mesut and Hooshyar, H. and Shen, Z. and Gajda, J. and Huq, K. M. M.}, year={2011} }
 @inproceedings{she_lukic_huang_bhattacharya_baran_2011, title={Performance evaluation of solid state transformer based microgrid in FREEDM systems}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-79955771308&partnerID=MN8TOARS}, DOI={10.1109/apec.2011.5744594}, abstractNote={A new concept of solid state transformer based microgrid system is presented in this paper. By utilizing 400V DC bus generated from Gen-I solid state transformer proposed by FREEDM systems center, integration issues of DC microgrid and solid state transformer are analyzed. Zonal DC microgrid concept is applied to this novel system with the consideration of burden minimization to the existing AC grid. The future grid architecture is described by using this solid state transformer based integrated microgrid system.}, booktitle={Annual ieee conference on applied power electronics conference and}, author={She, X. and Lukic, Srdjan and Huang, A. Q. and Bhattacharya, Subhashish and Baran, Mesut}, year={2011}, pages={182–188} }
 @inproceedings{baran_2011, title={Smart distribution system research and education at the FREEDM systems center}, DOI={10.1109/pes.2011.6039285}, abstractNote={This panel paper outlines the undergoing research towards the development of a novel smart distribution system at the Future Renewable Electric Energy Delivery and Management (FREEDM) Systems Center. The center's mission is to develop fundamental and enabling technologies necessary for a next generation smart distribution systems which can facilitate seamless integration of distributed recourses. The paper will also highlight center's education programs that are being developed for educating the next generation of power engineers who will be needed for the development and management of such systems.}, booktitle={2011 ieee power and energy society general meeting}, author={Baran, Mesut}, year={2011} }
 @article{she_she_baran_2011, title={Universal Tracking Control of Wind Conversion System for Purpose of Maximum Power Acquisition Under Hierarchical Control Structure}, volume={26}, ISSN={["1558-0059"]}, DOI={10.1109/tec.2011.2159607}, abstractNote={Renewable energy technologies have recently attracted intensive attentions. Several renewable energies, such as wind, solar, etc., are being investigated to solve current energy crisis. In this paper, a nonlinear controller is developed for tracking control of a wind energy conversion system under a hierarchical configuration. First, an adaptive neural-network-based estimator is developed to estimate uncertain (possibly unknown) aerodynamics online. Based on an estimated value of aerodynamics, a model-based adaptive tracking control law is derived based on the Lyapunov stability analysis. Associated dynamic parameter estimators are also developed to remove requirement of prior knowledge of system parameters. Then, robust differentiator techniques are utilized to eliminate the need for an acceleration of the wind and rotor. It is shown that the proposed controller can regulate tracking error to an arbitrary small value even if neither system parameter nor aerodynamics is available for control design. It is expected that the proposed control algorithm can be used as an “universal controller” for similar types of variable speed wind turbine with minimal modifications. The modularity of the proposed controller will enjoy the plug-and-play property that will be helpful in distributed control of smart grids. Simulation studies are performed along with the theoretical analysis to validate the proposed method.}, number={3}, journal={IEEE TRANSACTIONS ON ENERGY CONVERSION}, author={She, Yun and She, Xu and Baran, Mesut E.}, year={2011}, month={Sep}, pages={766–775} }
 @inproceedings{baran_steurer_2010, title={A digital testbed for FREEDM system development}, DOI={10.1109/pes.2010.5589690}, abstractNote={In this paper, a notional Future Renewable Electric Energy Delivery and Management (FREEDM) system has been developed based on a real distribution feeder. The goal is to develop a digital testbed which can be used to show capabilities of this system, and to help the development of especially the new system components and the control schemes for this system. Two digital testbeds have been developed, one to represent the small scale green hub that will be realized in the center's test facilities at North Carolina State University and the other is a more detailed notional system that can be used for large scale system level analysis and design.}, booktitle={Ieee power and energy soceity general meeting 2010}, author={Baran, Mesut and Steurer, M.}, year={2010} }
 @article{teleke_baran_bhattacharya_huang_2010, title={Optimal Control of Battery Energy Storage for Wind Farm Dispatching}, volume={25}, ISSN={["1558-0059"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-77956056892&partnerID=MN8TOARS}, DOI={10.1109/tec.2010.2041550}, abstractNote={Integrating a battery energy storage system (BESS) with a large wind farm can make a wind farm more dispatchable. This paper focuses on development of a control strategy for optimal use of the BESS for this purpose. The paper considers an open-loop optimal control scheme to incorporate the operating constraints of the BESS, such as state of charge limits, charge/discharge current limits, and lifetime. The goal of the control is to have the BESS to provide as much smoothing as possible, so that the wind farm can be dispatched on an hourly basis based on the forecasted wind conditions. The effectiveness of this control strategy has been tested by using an actual wind farm data. Furthermore, a real-time implementation strategy using model predictive control is also proposed. Finally, it is shown that the control strategy is very important in improving the BESS performance for this application.}, number={3}, journal={IEEE TRANSACTIONS ON ENERGY CONVERSION}, author={Teleke, Sercan and Baran, Mesut E. and Bhattacharya, Subhashish and Huang, Alex Q.}, year={2010}, month={Sep}, pages={787–794} }
 @inproceedings{zhao_zeng_bhattacharya_baran_huang_2009, title={An average model of solid state transformer for dynamic system simulation}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-71849090346&partnerID=MN8TOARS}, DOI={10.1109/pes.2009.5275542}, abstractNote={The Solid State Transformer (SST) is one of the key elements proposed in the National Science Foundation (NSF) Generation-III Engineering Research Center (ERC) “Future Renewable Electric Energy Delivery and Management” (FREEDM) Systems Center established in 2008. The SST is used to enable active management of distributed renewable energy resources, energy storage devices and loads. In this paper, a 20kVA solid state transformer based on 6.5kV IGBT is proposed for interface with 12kV distribution system voltage. The average model and control scheme of SST including AC/DC rectifier, Dual Active Bridge (DAB) converter and DC/AC inverter are developed to enable dynamic system level simulation. The developed average model is verified by comparing with the detailed switching model simulation. The dynamic system level SST simulation verifies the proposed controller and the corresponding average model illustrates the functionalities and advantages of the SST in FREEDM system.}, booktitle={2009 ieee power & energy society general meeting, vols 1-8}, author={Zhao, T. F. and Zeng, J. and Bhattacharya, Subhashish and Baran, Mesut and Huang, A. Q.}, year={2009}, pages={1516–1523} }
 @article{teleke_baran_huang_bhattacharya_anderson_2009, title={Control Strategies for Battery Energy Storage for Wind Farm Dispatching}, volume={24}, ISSN={["1558-0059"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-70049103778&partnerID=MN8TOARS}, DOI={10.1109/TEC.2009.2016000}, abstractNote={Integrating a battery energy storage system (BESS) with a large wind farm can smooth out the intermittent power from the wind farm. This paper focuses on development of a control strategy for optimal use of the BESS for this purpose. The paper considers a conventional feedback-based control scheme with revisions to incorporate the operating constraints of the BESS, such as state of charge limits, charge/discharge rate, and lifetime. The goal of the control is to have the BESS provide as much smoothing as possible so that the wind farm can be dispatched on an hourly basis based on the forecasted wind conditions. The effectiveness of this control strategy has been tested by using an actual wind farm data. Finally, it is shown that the control strategy is very important in determining the proper BESS size needed for this application.}, number={3}, journal={IEEE TRANSACTIONS ON ENERGY CONVERSION}, author={Teleke, Sercan and Baran, Mesut E. and Huang, Alex Q. and Bhattacharya, Subhashish and Anderson, Loren}, year={2009}, month={Sep}, pages={725–732} }
 @inproceedings{baran_mcdermott_2009, title={State estimation for real time monitoring of distribution feeders}, booktitle={2009 ieee power & energy society general meeting, vols 1-8}, author={Baran, M. and McDermott, T. E.}, year={2009}, pages={4153–4156} }
 @article{han_huang_baran_bhattacharya_litzenberger_anderson_johnson_edris_2008, title={STATCOM impact study on the integration of a large wind farm into a weak loop power system}, volume={23}, ISSN={["1558-0059"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-40849120152&partnerID=MN8TOARS}, DOI={10.1109/TEC.2006.888031}, abstractNote={Recently, renewable wind energy is enjoying a rapid growth globally to become an important green electricity source to replace polluting and exhausting fossil fuel. However, with wind being an uncontrollable resource and the nature of distributed wind induction generators, integrating a large-scale wind-farm into a power system poses challenges, particularly in a weak power system. In the paper, the impact of STATCOM to facilitate the integration of a large wind farm into a weak power system is studied. First, an actual weak power system with two nearby large wind farms is introduced. Based on the field SCADA data analysis, the power quality issues are highlighted and a centralized STATCOM is proposed to solve them, particularly the short-term (seconds to minutes) voltage fluctuations. Second, a model of the system, wind farm and STATCOM for steady-state and dynamic impact study is presented, and the model is validated by comparing with the actual field data. Using simulated PV and QV curves, voltage control and stability issues are analyzed, and the size and location of STATCOM are assessed. Finally, a STATCOM control strategy for voltage fluctuation suppression is presented and dynamic simulations verify the performance of proposed STATCOM and its control strategy}, number={1}, journal={IEEE TRANSACTIONS ON ENERGY CONVERSION}, author={Han, Chong and Huang, Alex Q. and Baran, Mesut E. and Bhattacharya, Subliashish and Litzenberger, Wayne and Anderson, Loren and Johnson, Anders L. and Edris, Abdel-Aty}, year={2008}, month={Mar}, pages={226–233} }
 @article{baran_el-markabi_2007, title={A multiagent-based dispatching scheme for distributed generators for voltage support on distribution feeders}, volume={22}, ISSN={["1558-0679"]}, DOI={10.1109/TPWRS.2006.889140}, abstractNote={This paper illustrates how a multiagent system (MAS)-based scheme can be developed for a control/optimization problem. The prototype problem considered is the dispatching of distributed generators on a distribution feeder to provide voltage support. The popular control net protocol (CNP) for MAS has been adopted to facilitate distributed control. This paper illustrates that characterization of the optimal solution is necessary in order to develop a protocol for the MAS to implement. This paper also shows that MAS facilitates a model-free control procedure, as it can monitor the local sensitivities. Test results, based on simulations on a prototype feeder, show that the proposed MAS-based control scheme is very effective in obtaining the solution for the prototype problem. The proposed method needs fast communication among the distributed generators (DGs) in order to assure fast response during emergency conditions. Communication requirements have also been identified in this paper}, number={1}, journal={IEEE TRANSACTIONS ON POWER SYSTEMS}, author={Baran, Mesut E. and El-Markabi, Ismail M.}, year={2007}, month={Feb}, pages={52–59} }
 @article{baran_mahajan_2007, title={Overcurrent protection on voltage-source-converter-based multiterminal DC distribution systems}, volume={22}, ISSN={["1937-4208"]}, DOI={10.1109/TPWRD.2006.877086}, abstractNote={This paper proposes a protection scheme which utilizes modern voltage-source converters as fast-acting current-limiting circuit breakers. This paper investigates the main challenges of detecting and localizing a fault, and interrupting it as quickly as possible in a multiterminal dc system. A system protection scheme consisting of smart relays associated with converters has been developed. The protection relays monitor local quantities to detect and isolate disturbances/faults. It is shown that overcurrent-based schemes can be adopted for these relays to meet the fast response requirements. The effectiveness of the proposed protection scheme is illustrated through simulations}, number={1}, journal={IEEE TRANSACTIONS ON POWER DELIVERY}, author={Baran, Mesut E. and Mahajan, Nikhil R.}, year={2007}, month={Jan}, pages={406–412} }
 @article{baran_kim_2006, title={A classifier for distribution feeder overcurrent analysis}, volume={21}, ISSN={["0885-8977"]}, DOI={10.1109/TPWRD.2005.852310}, abstractNote={This paper focuses on the problem of differentiating inrush currents from fault currents that are observed for a feeder at a distribution substation. This problem is important for feeder protection and power-quality monitoring purposes. The paper shows, using the actual field data, that it is not always easy to distinguish inrush currents from fault currents-as they do not have always well-defined waveforms. This paper shows that the two approaches-the Fourier transform, and the Wavelet transform can be adopted to extract features that make it possible to distinguish them from each other by using an artificial-neural-network-based classifier. The paper also illustrates how to address the issues for successful implementation of these schemes; such as prescreening of data, how to apply fast Fourier transform (FFT) and wavelet transform on the data, and the training of the artificial neural network in order to maximize the performance of the classifier. These issues are illustrated using the actual field data. The test results indicate that both FFT-based and wavelet-transform (WT)-based classifiers yield good results, but the WT-based classifier has better performance.}, number={1}, journal={IEEE TRANSACTIONS ON POWER DELIVERY}, author={Baran, ME and Kim, J}, year={2006}, month={Jan}, pages={456–462} }
 @article{baran_el-markaby_2005, title={Fault analysis on distribution feeders with distributed generators}, volume={20}, ISSN={["1558-0679"]}, DOI={10.1109/TPWRS.2005.857940}, abstractNote={This paper shows that the current an inverter interfaced distributed generator (IIDG) contributes to a fault varies considerably, due mainly to fast response of its controller. This paper proposes a method to extend the conventional fault analysis methods so that IIDG contribution can be estimated in the fault analysis. The proposed method gives rms profiles of the fault currents of interest (IIDG contribution and the fault currents the protective device will see). Test results, based on a prototype feeder, show that the proposed approach can estimate the fault current's contributions under both balanced and unbalanced fault conditions.}, number={4}, journal={IEEE TRANSACTIONS ON POWER SYSTEMS}, author={Baran, ME and El-Markaby, I}, year={2005}, month={Nov}, pages={1757–1764} }
 @article{baran_freeman_hanson_ayers_2005, title={Load estimation for load monitoring at distribution substations}, volume={20}, ISSN={["0885-8950"]}, DOI={10.1109/TPWRS.2004.840409}, abstractNote={This paper addresses the issues related to the real-time monitoring of loads at distribution substations. A method is proposed for estimating the measurements that become unavailable due to metering problems. To address the low redundancy associated with the load monitoring scheme, the method uses a regression-based model and makes use of the strong correlation between the loads that are geographically close to each other. The method was tested with actual field data. The results indicate that the method has the acceptable performance for measurement loss of up to a week. The average estimation error varies 2-7.5%, depending on which measurement is lost and how up-to-date the historical data is.}, number={1}, journal={IEEE TRANSACTIONS ON POWER SYSTEMS}, author={Baran, ME and Freeman, LAA and Hanson, F and Ayers, V}, year={2005}, month={Feb}, pages={164–170} }
 @article{baran_kim_hart_lubkeman_lampley_newell_2004, title={Voltage Variation Analysis for Site-Level PQ Assessment}, volume={19}, ISSN={0885-8977}, url={http://dx.doi.org/10.1109/tpwrd.2004.829951}, DOI={10.1109/TPWRD.2004.829951}, abstractNote={This paper investigates the challenges in developing a performance index that will reflect the level of power quality at a site based on the actual field data obtained from the site via power-quality (PQ) monitors. For the index, each observed voltage variation is assessed in terms of its potential to impact the customers served from the site. The paper considers the substation level PQ monitoring and adopts a procedure that is similar to one of the methods being proposed in the emerging IEEE guide 1564.}, number={4}, journal={IEEE Transactions on Power Delivery}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Baran, M.E. and Kim, J. and Hart, D.G. and Lubkeman, D. and Lampley, G.C. and Newell, W.F.}, year={2004}, month={Oct}, pages={1956–1961} }
 @article{baran_mahajan_2003, title={DC distribution for industrial systems: Opportunities and challenges}, volume={39}, ISSN={["1939-9367"]}, DOI={10.1109/TIA.2003.818969}, abstractNote={This paper investigates the opportunities and challenges associated with adopting a DC distribution scheme for industrial power systems. A prototype DC distribution system has been simulated to investigate the issues. One of the issues focused is the interaction between power converters that are used to convert AC to DC and DC to AC. Another challenging issue investigated is the system grounding. These issues become challenging mainly due to the neutral voltage shift associated with the power converters. The paper shows that converter interactions can be minimized with proper filtering and control on the converters. The paper also proposes a grounding scheme and shows that this scheme provides an effective solution by keeping the neutral voltages low under normal conditions and by limiting the fault currents during fault conditions. With these features, DC distribution provides very reliable and high-quality power.}, number={6}, journal={IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS}, author={Baran, ME and Mahajan, NR}, year={2003}, pages={1596–1601} }
 @article{baran_banunarayanan_garren_2000, title={Equitable allocation of congestion relief cost to transactions}, volume={15}, ISSN={["0885-8950"]}, DOI={10.1109/59.867144}, abstractNote={This paper investigates a bid based congestion management scheme for a system that accommodates many bilateral transactions. The paper proposes a new allocation method for allocating the cost of congestion relief to transactions that cause the congestion. The allocation reflects the actual usage of the congested facilities by the transactions and recovers the cost. Also proposed in the paper is a "consistency" test to quantify and test the equity/fairness of the method. Test results illustrate that the method provides better price signals for relieving congestion on lines than the shadow prices. The test results also indicate that the method recovers the cost. The results on consistency indicate that the proposed method is consistent provided that the transactions causing counterflows on congested lines be compensated.}, number={2}, journal={IEEE TRANSACTIONS ON POWER SYSTEMS}, author={Baran, ME and Banunarayanan, V and Garren, KE}, year={2000}, month={May}, pages={579–585} }
 @article{baran_banunarayanan_garren_1999, title={A transaction assessment method for allocation of transmission services}, volume={14}, ISSN={["0885-8950"]}, DOI={10.1109/59.780904}, abstractNote={This paper presents a power flow based method for an accurate assessment of the impact of a transaction on an area/utility. The method determines, for each transaction, the following: the flowpath of the transaction (both real and reactive power components); generator reactive power support from each area/utility; and real power loss support from each area/utility. The proposed method is tested extensively on a real-life system. Results indicate that the method is very accurate in allocating the above transmission services on a transaction basis.}, number={3}, journal={IEEE TRANSACTIONS ON POWER SYSTEMS}, author={Baran, ME and Banunarayanan, V and Garren, KE}, year={1999}, month={Aug}, pages={920–927} }
 @article{kelley_edwards_rhode_baran_1999, title={Transformer derating for harmonic currents: A wide-band measurement approach for energized transformers}, volume={35}, ISSN={["0093-9994"]}, DOI={10.1109/28.806061}, abstractNote={Power system transformers must often be derated when supplying harmonic currents to nonlinear loads. IEEE Recommended Practice C57.110 extrapolates transformer loss for harmonic frequencies based on DC winding resistance and rated eddy-current loss. This paper describes an improved derating technique based on direct measurements performed at fundamental and harmonic frequencies. The measurements can be performed regardless of whether the transformer is energized and in service or deenergized and out of service. For energized transformers, the measurement can be performed regardless of whether the transformer is fully loaded or unloaded. Measurements of several distribution transformers show the improvement of this method over C57.110.}, number={6}, journal={IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS}, author={Kelley, AW and Edwards, SW and Rhode, JP and Baran, ME}, year={1999}, pages={1450–1457} }
 @article{baran_hsu_1999, title={Volt/var control at distribution substations}, volume={14}, ISSN={["0885-8950"]}, DOI={10.1109/59.744549}, abstractNote={This paper proposes new methods to improve the performance of the current volt/VAr control schemes at distribution substations. The approach makes use of the new measurement and computer resources that are now available at the substations. The paper shows that new supervisory type control schemes can be developed to improve the performance of both the voltage regulator controllers and also the substation capacitor controllers that are used at the substations for volt/VAr control. The new voltage regulator controller makes use of the voltage drop characteristics of the feeders it regulates. The capacitor controller uses local real and reactive power measurements for power factor control at the substation.}, number={1}, journal={IEEE TRANSACTIONS ON POWER SYSTEMS}, author={Baran, ME and Hsu, MY}, year={1999}, month={Feb}, pages={312–318} }
 @article{baran_maclaga_kelley_craven_1998, title={Effects of tower disturbances on computer systems}, volume={13}, ISSN={["0885-8977"]}, DOI={10.1109/61.714501}, abstractNote={This paper investigates the effects of electrical disturbances on a computer system consisting of PCs interconnected together with data cables-a PC LAN. The computer system was subjected to the following three types of electrical disturbances: power disturbances from the utility; local disturbances from nearby end-use devices; and RFI from industrial equipment. Test results indicate that a well configured PC LAN is quite immune to most utility power disturbances, but some local disturbances, especially RFI, can degrade the performance of the system considerably. Test results also give important hints towards investigating power quality problems related to computer loads.}, number={4}, journal={IEEE TRANSACTIONS ON POWER DELIVERY}, author={Baran, ME and Maclaga, J and Kelley, AW and Craven, K}, year={1998}, month={Oct}, pages={1309–1315} }
 @article{rhode_kelley_baran_1997, title={Complete characterization of utilization-voltage power system impedance using wideband measurement}, volume={33}, ISSN={["0093-9994"]}, DOI={10.1109/28.649958}, abstractNote={Inexpensive portable instrumentation is used to measure the impedance of an example utilization-voltage power system, With the power system in normal operation, line-to-neutral, line-to-ground and neutral-to-ground impedances are measured over a bandwidth of 20 Hz-24 kHz. The measured impedance is presented as resistance and inductance, which vary with frequency. Based on the measurements, additional calculations are performed to find the resistance and inductance of every conductor in the system. This complete wide-band characterization of power system impedance provides valuable data for power quality calculations.}, number={6}, journal={IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS}, author={Rhode, JP and Kelley, AW and Baran, ME}, year={1997}, pages={1472–1479} }
 @article{baran_staton_1997, title={Distribution transformer models for branch current based feeder analysis}, volume={12}, ISSN={["0885-8950"]}, DOI={10.1109/59.589655}, abstractNote={This paper proposes a new method to include distribution transformers in feeder analysis. The proposed method tailors the transformer models specifically for the branch current based feeder analysis method. The approach is general in that it can be used to represent any type of transformer. The analysis method is computationally very efficient and the paper shows that the proposed transformer models preserve the computational efficiency of this method. Transformer models in the branch current based method enables one to analyze distribution systems in more detail.}, number={2}, journal={IEEE TRANSACTIONS ON POWER SYSTEMS}, author={Baran, ME and Staton, EA}, year={1997}, month={May}, pages={698–703} }