@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{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{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{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} }