Advanced Droop Control Strategies for Microgrid

International Journal of Electrical and Electronics Engineering

© 2024 by SSRG - IJEEE Journal

Volume 11 Issue 12

Year of Publication : 2024

Authors : Seema P. Diwan, Rajin M. Linus

10.14445/23488379/IJEEE-V11I12P132

How to Cite?

Seema P. Diwan, Rajin M. Linus, "Advanced Droop Control Strategies for Microgrid," SSRG International Journal of Electrical and Electronics Engineering, vol. 11,  no. 12, pp. 335-360, 2024. Crossref, https://doi.org/10.14445/23488379/IJEEE-V11I12P132

Abstract:

This article reviews the current landscape of droop control methods in Microgrids (MG), specifically focusing on advanced, communication-less strategies that enhance real and reactive power sharing accuracy. While widely utilised, Conventional Droop Control (CDC) techniques often struggle with power sharing inaccuracies and dynamic response inefficiencies, particularly in systems with resistive, complex or mismatched line impedances. This review introduces a novel and systematic classification of advanced droop control strategies aimed at addressing these limitations. The proposed classification categorizes methods based on their ability to improve power-sharing precision in different scenarios, including Low-Voltage (LV) MGs with resistive lines, Medium-Voltage (MV) systems with complex feeder impedances, dynamic loading conditions, and mismatched line impedance scenarios. For example, virtual impedance-based droop methods enhance reactive power sharing in mismatched impedances, while reverse droop control improves power sharing in resistive LV networks. Power decoupling transforms are also employed to enhance power-sharing precision in complex and resistive MG. This review also provides an in-depth analysis of the CDC, with its limitations verified through extensive simulations. A comparative study of advanced droop methods based on key parameters clearly explains their applicability in various operational scenarios. The findings are validated through simulations, providing practical insights into using advanced droop control methods in MG.

Keywords:

Microgrid, Conventional Droop Control, Active power sharing, Power management in microgrid, Reactive Power Sharing, Inaccuracies in power sharing, Classification of Droop Control.

References:

[1] Fatih Birol, “World Energy Outlook 2024”, International Energy Agency, Technical Report, 2024.
[Publisher Link]
[2] Roger Lawrence, and S. Middlekauff, “The New Guy on the Block,” IEEE Industry Applications Magazine, vol. 11, no. 1, pp. 54-59, 2005.
[CrossRef] [Google Scholar] [Publisher Link]
[3] Sheng Su, YinHong Li, and XianZhong Duan, “Self-Organized Criticality of Power System Faults and Its Application in Adaptation to Extreme Climate,” Chinese Science Bulletin, vol. 54, no. 7, pp. 1251-1259, 2009.
[CrossRef] [Google Scholar] [Publisher Link]
[4] B. Satish, and S. Bhuvaneswari, “Control of Microgrid - A Review,” International Conference on Advances in Green Energy (ICAGE), Thiruvananthapuram, India, pp. 18-25, 2014.
[CrossRef] [Google Scholar] [Publisher Link]
[5] Han Minxiao et al., “Transient Analysis and Control for Microgrid Stability Controller,” IEEE Grenoble Conference, Grenoble, France, pp. 1-6, 2013.
[CrossRef] [Google Scholar] [Publisher Link]
[6] Yao Zhang, and Hao Ma, “Theoretical and Experimental Investigation of Networked Control for Parallel Operation of Inverters,” IEEE Transactions on Industrial Electronics, vol. 59, no. 4, pp. 1961-1970, 2012.
[CrossRef] [Google Scholar] [Publisher Link]
[7] Yun Wei Li, and Ching-Nan Kao, “An Accurate Power Control Strategy for Power-Electronics-Interfaced Distributed Generation Units Operating in a Low-Voltage Multibus Microgrid,” IEEE Transactions on Power Electronics, vol. 24, no. 12, pp. 2977-2988, 2009.
[CrossRef] [Google Scholar] [Publisher Link]
[8] Qiang Fu et al., “Microgrid Generation Capacity Design with Renewables and Energy Storage Addressing Power Quality and Surety,” IEEE Transactions on Smart Grid, vol. 3, no. 4, pp. 2019-2027, 2012.
[CrossRef] [Google Scholar] [Publisher Link]
[9] Farid Katiraei, and M. Reza Iravani, “Power Management Strategies for a Microgrid with Multiple Distributed Generation Units,” IEEE Transactions on Power Systems, vol. 21, no. 4, pp. 1821-1831, 2006.
[CrossRef] [Google Scholar] [Publisher Link]
[10] Paolo Piagi, and Robert H. Lasseter, “Autonomous Control of Microgrids,” IEEE Power Engineering Society General Meeting, Montreal, QC, Canada, 2006.
[CrossRef] [Google Scholar] [Publisher Link]
[11] Z. Zeng, H. Yang, and R. Zhao, “Study on Small Signal Stability of Microgrids: A Review and a New Approach,” Renewable and Sustainable Energy Reviews, vol. 15, no. 9, pp. 4818-4828, 2011.
[CrossRef] [Google Scholar] [Publisher Link]
[12] Frede Blaabjerg et al., “Overview of Control and Grid Synchronization for Distributed Power Generation Systems,” IEEE Transactions on Industrial Electronics, vol. 53, no. 5, pp. 1398-1409, 2006.
[CrossRef] [Google Scholar] [Publisher Link]
[13] Robert H. Lasseter, and P. Paigi, “Microgrid: A Conceptual Solution,” IEEE 35th Annual Power Electronics Specialists Conference (IEEE Cat. No.04CH37551), Aachen, Germany, vol. 6, pp. 4285-4290, 2004.
[CrossRef] [Google Scholar] [Publisher Link]
[14] Zhi Chen et al., “An Adaptive Virtual Resistor (AVR) Control Strategy for Low-Voltage Parallel Inverters,” IEEE Transactions on Power Electronics, vol. 34, no. 1, pp. 863-876, 2019.
[CrossRef] [Google Scholar] [Publisher Link]
[15] Chia-Tse Lee, Chia-Chi Chu, and Po-Tai Cheng, “A New Droop Control Method for the Autonomous Operation of Distributed Energy Resource Interface Converters,” IEEE Transactions on Power Electronics, vol. 28, no. 4, pp. 1980-1993, 2013.
[CrossRef] [Google Scholar] [Publisher Link]
[16] Qing-Chang Zhong, “Robust Droop Controller for Accurate Proportional Load Sharing Among Inverters Operated in Parallel,” IEEE Transactions on Industrial Electronics, vol. 60, no. 4, pp. 1281-1290, 2013.
[CrossRef] [Google Scholar] [Publisher Link]
[17] Daniel E. Olivares et al., “Trends in Microgrid Control,” IEEE Transactions on Smart Grid, vol. 5, no. 4, pp. 1905-1919, 2014.
[CrossRef] [Google Scholar] [Publisher Link]
[18] Karel De Brabandere et al., “A Voltage and Frequency Droop Control Method for Parallel Inverters,” IEEE Transactions on Power Electronics, vol. 22, no. 4, pp. 1107-1115, 2007.
[CrossRef] [Google Scholar] [Publisher Link]
[19] Yunwei Li, D. Mahinda Vilathgamuwa, and Poh Chiang Loh, “Design, Analysis, and Real-Time Testing of a Controller for Multibus Microgrid System,” IEEE Transactions on Power Electronics, vol. 19, no. 5, pp. 1195-1204, 2004.
[CrossRef] [Google Scholar] [Publisher Link]
[20] Charles Sao, and Peter W. Lehn, “Autonomous Load Sharing of Voltage Source Converters,” IEEE Transactions on Power Delivery, vol. 20, no. 2, pp. 1009-1016, 2005.
[CrossRef] [Google Scholar] [Publisher Link]
[21] Hassan Nikkhajoei, and Robert H. Lasseter, “Distributed Generation Interface to the CERTS Microgrid,” IEEE Transactions on Power Delivery, vol. 24, no. 3, pp. 1598-1608, 2009.
[CrossRef] [Google Scholar] [Publisher Link]
[22] A. Tuladhar et al., “Parallel Operation of Single Phase Inverter Modules with No Control Interconnections,” Proceedings of APEC 97 - Applied Power Electronics Conference, Atlanta, GA, USA, vol. 1, pp. 94-100, 1997.
[CrossRef] [Google Scholar] [Publisher Link]
[23] A. Tuladhar et al., “Control of Parallel Inverters in Distributed AC Power Systems with Consideration of Line Impedance Effect,” IEEE Transactions on Industry Applications, vol. 36, no. 1, pp. 131-138, 2000.
[CrossRef] [Google Scholar] [Publisher Link]
[24] Juan C. Vasquez et al., “Adaptive Droop Control Applied to Voltage-Source Inverters Operating in Grid-Connected and Islanded Modes,” IEEE Transactions on Industrial Electronics, vol. 56, no. 10, pp. 4088-4096, 2009.
[CrossRef] [Google Scholar] [Publisher Link]
[25] Jinwei He, and Yun Wei Li, “An Enhanced Microgrid Load Demand Sharing Strategy,” IEEE Transactions on Power Electronics, vol. 27, no. 9, pp. 3984-3995, 2012.
[CrossRef] [Google Scholar] [Publisher Link]
[26] Chia-Tse Lee et al., “Control Strategies for Distributed Energy Resources Interface Converters in the Low Voltage Microgrid,” IEEE Energy Conversion Congress and Exposition, San Jose, CA, USA, pp. 2022-2029, 2009.
[CrossRef] [Google Scholar] [Publisher Link]
[27] Christopher N. Rowe et al., “Implementing The Virtual Output Impedance Concept in a Three Phase System Utilising Cascaded PI Controllers in the Dq Rotating Reference Frame for Microgrid Inverter Control,” 15th European Conference on Power Electronics and Applications (EPE), Lille, France, pp. 1-10, 2013.
[CrossRef] [Google Scholar] [Publisher Link]
[28] Yan Li, and Yun Wei Li, “Decoupled Power Control for an Inverter Based Low Voltage Microgrid in Autonomous Operation,” IEEE 6th International Power Electronics and Motion Control Conference, pp. 2490-2496, 2009.
[CrossRef] [Google Scholar] [Publisher Link]
[29] Yan Li, and Yun Wei Li, “Power Management of Inverter Interfaced Autonomous Microgrid Based on Virtual Frequency-Voltage Frame,” IEEE Transactions on Smart Grid, vol. 2, no. 1, pp. 30-40, 2011.
[CrossRef] [Google Scholar] [Publisher Link]
[30] Yan Li, and Yun Wei Li, “Virtual Frequency-Voltage Frame Control of Inverter Based Low Voltage Microgrid,” IEEE Electrical Power and Energy Conference (EPEC), Montreal, QC, Canada, pp. 1-6, 2009.
[CrossRef] [Google Scholar] [Publisher Link]
[31] Guolian Hou et al., “Virtual Negative Impedance Droop Method for Parallel Inverters in Microgrids,” IEEE 10th Conference on Industrial Electronics and Applications (ICIEA), Auckland, New Zealand, pp. 1009-1013, 2015.
[CrossRef] [Google Scholar] [Publisher Link]
[32] Wei Yao et al., “Design and Analysis of the Droop Control Method for Parallel Inverters Considering the Impact of the Complex Impedance on the Power Sharing,” IEEE Transactions on Industrial Electronics, vol. 58, no. 2, pp. 576-588, 2011.
[CrossRef] [Google Scholar] [Publisher Link]
[33] Ahmed Moawwad, Vinod Khadkikar, and James L. Kirtley, “A New P-Q-V Droop Control Method for an Interline Photovoltaic (I-PV) Power System,” IEEE Transactions on Power Delivery, vol. 28, no. 2, pp. 658-668, 2013.
[CrossRef] [Google Scholar] [Publisher Link]
[34] Ritwik Majumder et al., “Improvement of Stability and Load Sharing in an Autonomous Microgrid Using Supplementary Droop Control Loop,” IEEE Transactions on Power Systems, vol. 25, no. 2, pp. 796-808, 2010.
[CrossRef] [Google Scholar] [Publisher Link]
[35] Hyun-Koo Kang, Seon-Ju Ahn, and Seung-Il Moon, “A New Method to Determine the Droop of Inverter-Based DGs,” IEEE Power and Energy Society General Meeting, Calgary, AB, Canada, pp. 1-6, 2009.
[CrossRef] [Google Scholar] [Publisher Link]
[36] Chia-Tse Lee, Chia-Chi Chu, and Po-Tai Cheng, “A New Droop Control Method for the Autonomous Operation of Distributed Energy Resource Interface Converters,” IEEE Energy Conversion Congress and Exposition, Atlanta, GA, USA, pp. 702-709, 2010.
[CrossRef] [Google Scholar] [Publisher Link]
[37] Christopher N. Rowe et al., “Arctan Power-Frequency Droop for Improved Microgrid Stability,” IEEE Transactions on Power Electronics, vol. 28, no. 8, pp. 3747-3759, 2013.
[CrossRef] [Google Scholar] [Publisher Link]
[38] Jiefeng Hu et al., “Virtual Flux Droop Method-A New Control Strategy of Inverters in Microgrids,” IEEE Transactions on Power Electronics, vol. 29, no. 9, pp. 4704-4711, 2014.
[CrossRef] [Google Scholar] [Publisher Link]
[39] E. Rokrok, and M.E.H. Golshan, “Adaptive Voltage Droop Scheme for Voltage Source Converters in an Islanded Multibus Microgrid,” IET Generation, Transmission and Distribution, vol. 4, no. 5, pp. 562-578, 2010.
[CrossRef] [Google Scholar] [Publisher Link]
[40] Jung-Won Kim, Hang-Seok Choi, and Bo Hyung Cho, “A Novel Droop Method for Converter Parallel Operation,” IEEE Transactions on Power Electronics, vol. 17, no. 1, pp. 25-32, 2002.
[CrossRef] [Google Scholar] [Publisher Link]
[41] Yasser Abdel-Rady Ibrahim Mohamed, and Ehab F. El-Saadany, “Adaptive Decentralized Droop Controller to Preserve Power Sharing Stability of Paralleled Inverters in Distributed Generation Microgrids,” IEEE Transactions on Power Electronics, vol. 23, no. 6, pp. 2806-2816, 2008.
[CrossRef] [Google Scholar] [Publisher Link]
[42] Jaehong Kim et al., “Mode Adaptive Droop Control with Virtual Output Impedances for an Inverter-Based Flexible AC Microgrid,” IEEE Transactions on Power Electronics, vol. 26, no. 3, pp. 689-701, 2011.
[CrossRef] [Google Scholar] [Publisher Link]
[43] Usman Bashir Tayab et al., “A Review of Droop Control Techniques For Microgrid,” Renewable and Sustainable Energy Reviews, vol. 76, pp. 717-727, 2017.
[CrossRef] [Google Scholar] [Publisher Link]
[44] Saroja Kanti Sahoo, Avinash Kumar Sinha, and N. Krishna Kishore, “Control Techniques in AC, DC, and Hybrid AC-DC Microgrid: A Review,” IEEE Journal of Emerging and Selected Topics in Power Electronics, vol. 6, no. 2, pp. 738-759, 2018.
[CrossRef] [Google Scholar] [Publisher Link]
[45] Jiefeng Hu et al., “Overview of Power Converter Control in Microgrids-Challenges, Advances, and Future Trends,” IEEE Transactions on Power Electronics, vol. 37, no. 8, pp. 9907-9922, 2022.
[CrossRef] [Google Scholar] [Publisher Link]
[46] Ajay Gupta, Suryanarayana Doolla, and Kishore Chatterjee, “Hybrid AC–DC Microgrid: Systematic Evaluation of Control Strategies,” IEEE Transactions on Smart Grid, vol. 9, no. 4, pp. 3830-3843, 2018.
[CrossRef] [Google Scholar] [Publisher Link]
[47] Kafeel Ahmed et al., “A Review on Primary and Secondary Controls of Inverter-Interfaced Microgrid,” Journal of Modern Power Systems and Clean Energy, vol. 9, no. 5, pp. 969-985, 2021.
[CrossRef] [Google Scholar] [Publisher Link]
[48] Farid Katiraei, M. Reza Iravani, and Peter W. Lehn, “Micro-Grid Autonomous Operation During and Subsequent to Islanding Process,” IEEE Power Engineering Society General Meeting, Denver, CO, USA, vol. 2, 2004.
[CrossRef] [Google Scholar] [Publisher Link]
[49] Fang Gao, and M. Reza Iravani, “A Control Strategy for a Distributed Generation Unit in Grid-Connected and Autonomous Modes of Operation,” IEEE Transactions on Power Delivery, vol. 23, no. 2, pp. 850-859, 2008.
[CrossRef] [Google Scholar] [Publisher Link]
[50] Mukul C. Chandorkar, Deepakraj M. Divan, and Ram Adapa, “Control of Parallel Connected Inverters in Standalone AC Supply Systems,” IEEE Transactions on Industry Applications, vol. 29, no. 1, pp. 136-143, 1993.
[CrossRef] [Google Scholar] [Publisher Link]
[51] Santanu K. Mishra, “Design-Oriented Analysis of Modern Active Droop-Controlled Power Supplies,” IEEE Transactions on Industrial Electronics, vol. 56, no. 9, pp. 3704-3708, 2009.
[CrossRef] [Google Scholar] [Publisher Link]
[52] Min Dai et al., “Power Flow Control of A Single Distributed Generation Unit with Nonlinear Local Load,” IEEE PES Power Systems Conference and Exposition, New York, NY, USA, vol. 1, pp. 398-403, 2004.
[CrossRef] [Google Scholar] [Publisher Link]
[53] Josep M. Guerrero, Lijun Hang, and Javier Uceda, “Control of Distributed Uninterruptible Power Supply Systems,” IEEE Transactions on Industrial Electronics, vol. 55, no. 8, pp. 2845-2859, 2008.
[CrossRef] [Google Scholar] [Publisher Link]
[54] Po-Tai Cheng et al., “A Cooperative Imbalance Compensation Method for Distributed-Generation Interface Converters,” IEEE Transactions on Industry Applications, vol. 45, no. 2, pp. 805-815, 2009.
[CrossRef] [Google Scholar] [Publisher Link]
[55] Xiaodan Bai, Hong Miao, and Chengbi Zeng, “Improved Droop Control Strategy for Reactive Power Sharing of Parallel Inverters In Low-Voltage Microgrid,” IEEE Innovative Smart Grid Technologies - Asia (ISGT Asia), Chengdu, China, pp. 2538-2543, 2019.
[CrossRef] [Google Scholar] [Publisher Link]
[56] Ernane Antônio Alves Coelho, Porfrio Cabaleiro Cortizo, and Pedro F. Donoso Garcia, “Small-Signal Stability for Parallel-Connected Inverters in Stand-Alone AC Supply Systems,” IEEE Transactions on Industry Applications, vol. 38, no. 2, pp. 533-542, 2002.
[CrossRef] [Google Scholar] [Publisher Link]
[57] Nagaraju Pogaku, Milan Prodanovic, and Timothy C. Green, “Modeling, Analysis and Testing of Autonomous Operation of an Inverter-Based Microgrid,” IEEE Transactions on Power Electronics, vol. 22, no. 2, pp. 613-625, 2007.
[CrossRef] [Google Scholar] [Publisher Link]
[58] Yunwei Ryan Li, Farzam Nejabatkhah, and Hao Tian, Smart Hybrid AC/DC Microgrids: Power Management, Energy Management, and Power Quality Control, John Wiley & Sons, Ltd, 2022.
[Google Scholar] [Publisher Link]
[59] Yasser Abdel-Rady I. Mohamed, and Amr A. Radwan, “Hierarchical Control System for Robust Microgrid Operation and Seamless Mode Transfer in Active Distribution Systems,” IEEE Transactions on Smart Grid, vol. 2, no. 2, pp. 352-362, 2011.
[CrossRef] [Google Scholar] [Publisher Link]
[60] Alireza Kahrobaeian, and Yasser Abdel-Rady Ibrahim Mohamed, “Networked-Based Hybrid Distributed Power Sharing and Control for Islanded Microgrid Systems,” IEEE Transactions on Power Electronics, vol. 30, no. 2, pp. 603-617, 2015.
[CrossRef] [Google Scholar] [Publisher Link]
[61] Inam Ullah Nutkani et al., “Linear Decentralized Power Sharing Schemes for Economic Operation of AC Microgrids,” IEEE Transactions on Industrial Electronics, vol. 63, no. 1, pp. 225-234, 2016.
[CrossRef] [Google Scholar] [Publisher Link]
[62] Josep M. Guerrero et al., “Decentralized Control for Parallel Operation of Distributed Generation Inverters Using Resistive Output Impedance,” IEEE Transactions on Industrial Electronics, vol. 54, no. 2, pp. 994-1004, 2007.
[CrossRef] [Google Scholar] [Publisher Link]
[63] Josep M. Guerrero et al., “Control Strategy for Flexible Microgrid Based on Parallel Line-Interactive UPS Systems,” IEEE Transactions on Industrial Electronics, vol. 56, no. 3, pp. 726-736, 2009.
[CrossRef] [Google Scholar] [Publisher Link]
[64] Xiaoxiao Yu et al., “Control of Parallel-Connected Power Converters for Low-Voltage Microgrid-Part I: A Hybrid Control Architecture,” IEEE Transactions on Power Electronics, vol. 25, no. 12, pp. 2962-2970, 2010.
[CrossRef] [Google Scholar] [Publisher Link]
[65] Dan Wu, Fen Tang, J.C. Vasquez, and J.M. Guerrero, “Control and Analysis of Droop and Reverse Droop Controllers for Distributed Generations,” IEEE 11th International Multi-Conference on Systems, Signals and Devices (SSD14), Barcelona, Spain, 2014, pp. 1-5, 2014.
[CrossRef] [Google Scholar] [Publisher Link]
[66] Josep Maria Guerrero et al., “Output Impedance Design of Parallel-Connected UPS Inverters with Wireless Load-Sharing Control,” IEEE Transactions on Industrial Electronics, vol. 52, no. 4, pp. 1126-1135, 2005.
[CrossRef] [Google Scholar] [Publisher Link]
[67] Charles K. Sao, and Peter W. Lehn, “Control and Power Management of Converter Fed Microgrids,” IEEE Transactions on Power Systems, vol. 23, no. 3, pp. 1088-1098, 2008.
[CrossRef] [Google Scholar] [Publisher Link]
[68] Hua Han et al., “Review of Power Sharing Control Strategies for Islanding Operation of AC Microgrids,” IEEE Transactions on Smart Grid, vol. 7, no. 1, pp. 200-215, 2016.
[CrossRef] [Google Scholar] [Publisher Link]
[69] Saheb Khanabdal et al., “Adaptive Virtual Flux Droop Control Based on Virtual Impedance in Islanded AC Microgrids,” IEEE Journal of Emerging and Selected Topics in Power Electronics, vol. 10, no. 1, pp. 1095-1107, 2022.
[CrossRef] [Google Scholar] [Publisher Link]
[70] II-Yop Chung et al., :Control Methods of Inverter-Interfaced Distributed Generators in a Microgrid System,” IEEE Transactions on Industry Applications, vol. 46, no. 3, pp. 1078-1088, 2010.
[CrossRef] [Google Scholar] [Publisher Link]
[71] Jiuyang Zhou, and Po-Tai Cheng, “A Modified Q-V̇ Droop Control for Accurate Reactive Power Sharing in Distributed Generation Microgrid,” IEEE Transactions on Industry Applications, vol. 55, no. 4, pp. 4100-4109, 2019.
[CrossRef] [Google Scholar] [Publisher Link]
[72] Tine L. Vandoorn et al., “Automatic Power-Sharing Modification of P/V Droop Controllers in Low-Voltage Resistive Microgrids,” IEEE Transactions on Power Delivery, vol. 27, no. 4, pp. 2318-2325, 2012.
[CrossRef] [Google Scholar] [Publisher Link]
[73] Jianbo Chen et al., “A Virtual Complex Impedance Based P-V̇ Droop Method for Parallel-Connected Inverters in Low-Voltage AC Microgrids,” IEEE Transactions on Industrial Informatics, vol. 17, no. 3, pp. 1763-1773, 2021.
[CrossRef] [Google Scholar] [Publisher Link]
[74] Alfred Engler, “Control of Parallel Operating Battery Inverters,” Photovoltaic Hybrid Power Systems Conference, Aix-en-Provence, pp. 1-4, 2000.
[Google Scholar]
[75] S.J. Chiang, Chih-Ying Yen, and Kuo-Tsai Chang, “A Multimodule Parallelable Series-Connected PWM Voltage Regulator,” IEEE Transactions on Industrial Electronics, vol. 48, no. 3, pp. 506-516, 2001.
[CrossRef] [Google Scholar] [Publisher Link]
[76] Josep M. Guerrero et al., “Hierarchical Control of Droop-Controlled AC and DC Microgrids-A General Approach Toward Standardization,” IEEE Transactions on Industrial Electronics, vol. 58, no. 1, pp. 158-172, 2011.
[CrossRef] [Google Scholar] [Publisher Link]
[77] Josep Maria Guerrero et al., “Wireless-Control Strategy for Parallel Operation of Distributed-Generation Inverters,” IEEE Transactions on Industrial Electronics, vol. 53, no. 5, pp. 1461-1470, 2006.
[CrossRef] [Google Scholar] [Publisher Link]
[78] Josep M. Guerrero et al., “Advanced Control Architectures for Intelligent Microgrids-Part I: Decentralized and Hierarchical Control,” IEEE Transactions on Industrial Electronics, vol. 60, no. 4, pp. 1254-1262, 2013.
[CrossRef] [Google Scholar] [Publisher Link]
[79] Alexander Micallef et al., “Reactive Power Sharing and Voltage Harmonic Distortion Compensation of Droop Controlled Single Phase Islanded Microgrids,” IEEE Transactions on Smart Grid, vol. 5, no. 3, pp. 1149-1158, 2014.
[CrossRef] [Google Scholar] [Publisher Link]
[80] Mehdi Savaghebi et al., “Autonomous Voltage Unbalance Compensation in an Islanded Droop-Controlled Microgrid,” IEEE Transactions on Industrial Electronics, vol. 60, no. 4, pp. 1390-1402, 2013.
[CrossRef] [Google Scholar] [Publisher Link]
[81] Zishun Peng et al., “Droop Control Strategy Incorporating Coupling Compensation and Virtual Impedance for Microgrid Application,” IEEE Transactions on Energy Conversion, vol. 34, no. 277-291, 2019.
[CrossRef] [Google Scholar] [Publisher Link]
[82] Allal M. Bouzid et al., “A Survey on Control of Electric Power Distributed Generation Systems for Microgrid Applications,” Renewable and Sustainable Energy Reviews, vol. 44, pp.751-766, 2015.
[CrossRef] [Google Scholar] [Publisher Link]
[83] Moudud Ahmed et al., “Adaptive Virtual Impedance Controller for Parallel and Radial Microgrids With Varying X/R Ratios,” IEEE Transactions on Sustainable Energy, vol. 13, no. 2, pp. 830-843, 2022.
[CrossRef] [Google Scholar] [Publisher Link]
[84] A.S. Vijay et al., “An Adaptive Virtual Impedance Control for Improving Power Sharing among Inverters in Islanded AC Microgrids,” IEEE Transactions on Smart Grid, vol. 12, no. 4, pp. 2991-3003, 2021.
[CrossRef] [Google Scholar] [Publisher Link]
[85] Baojin Liu et al., “An Adaptive Virtual Impedance Control Scheme Based on Small-AC-Signal Injection for Unbalanced and Harmonic Power Sharing in Islanded Microgrids,” IEEE Transactions on Power Electronics, vol. 34, no. 12, pp. 12333-12355, 2019.
[CrossRef] [Google Scholar] [Publisher Link]
[86] Hisham Mahmood, Dennis Michaelson, and Jin Jiang, “Accurate Reactive Power Sharing in an Islanded Microgrid Using Adaptive Virtual Impedances,” IEEE Transactions on Power Electronics, vol. 30, no. 3, pp. 1605-1617, 2015.
[CrossRef] [Google Scholar] [Publisher Link]
[87] Baoze Wei et al., “DAVIC: A New Distributed Adaptive Virtual Impedance Control for Parallel-Connected Voltage Source Inverters in Modular UPS System,” IEEE Transactions on Power Electronics, vol. 34, no. 6, pp. 5953-5968, 2019.
[CrossRef] [Google Scholar] [Publisher Link]
[88] Tuan V. Hoang, and Hong-Hee Lee, “An Adaptive Virtual Impedance Control Scheme to Eliminate the Reactive-Power-Sharing Errors in an Islanding Meshed Microgrid,” IEEE Journal of Emerging and Selected Topics in Power Electronics, vol. 6, no. 2, pp. 966-976, 2018.
[CrossRef] [Google Scholar] [Publisher Link]
[89] Mohsen Eskandari et al., “A Control System for Stable Operation of Autonomous Networked Microgrids,” IEEE Transactions on Power Delivery, vol. 35, no. 4, pp. 1633-1647, 2020.
[CrossRef] [Google Scholar] [Publisher Link]
[90] Hamid Reza Baghaee et al., “Unbalanced Harmonic Power Sharing and Voltage Compensation of Microgrids Using Radial Basis Function Neural Network-Based Harmonic Power-Flow Calculations for Distributed and Decentralised Control Structures,” IET Generation, Transmission and Distribution, vol. 12, no. 7, pp. 1518-1530, 2018.
[CrossRef] [Google Scholar] [Publisher Link]
[91] Hamid Reza Baghae et al., “Nonlinear Load Sharing and Voltage Compensation of Microgrids Based on Harmonic Power-Flow Calculations Using Radial Basis Function Neural Networks,” IEEE Systems Journal, vol. 12, no. 3, pp. 2749-2759, 2018.
[CrossRef] [Google Scholar] [Publisher Link]
[92] David J. Perreault, R.L. Selders, and John G. Kassakian, “Frequency-Based Current-Sharing Techniques For Paralleled Power Converters,” IEEE Transactions on Power Electronics, vol. 13, no. 4, pp. 626-634, 1998.
[CrossRef] [Google Scholar] [Publisher Link]
[93] M. Hamzeh, H. Mokhtari, and H. Karimi, “A Decentralized Self-Adjusting Control Strategy for Reactive Power Management in an Islanded Multi-Bus MV Microgrid,” Canadian Journal of Electrical and Computer Engineering, vol. 36, no. 1, pp. 18-25, 2013.
[CrossRef] [Google Scholar] [Publisher Link]
[94] M.A. Parvez Mahmud et al., “Robust Nonlinear Distributed Controller Design for Active and Reactive Power Sharing in Islanded Microgrids,” IEEE Transactions on Energy Conversion, vol. 29, no. 4, pp. 893-903, 2014.
[CrossRef] [Google Scholar] [Publisher Link]
[95] Alfred Engler, “Applicability of Droops in Low Voltage Grids,” International Journal of Distributed Energy Resources, vol. 1, no. 1, pp. 1-6, 2005.
[Google Scholar]