Research on the Analysis of Virtual Synchronous Generator Voltage Support Influence Factors and Improvement Control Strategies Based on Equivalent Impedance
Liu Sijia1, Liu Haitao2, Zhang Jun2, Yu Siqi2, Sun Dawei2, Xing Jing2, Gao Benfeng1
1. Hebei Key Laboratory of Distributed Energy Storage and Micro-Grid North China Electric Power University Baoding 071003 China; 2. State Grid Jibei Electric Power Co. Ltd Beijing 100054 China
Abstract：Under the impetus of "dual carbon" targets, new energy sources are increasingly integrated into the power grid through power electronic converters, leading to a gradual decline in the proportion of synchronous machines. To enhance the stability of "highly renewable and highly flexible" systems, the flexible controllability of converters can be leveraged by employing grid-forming control to provide reliable voltage and frequency support to the system. Virtual synchronous generator (VSG) control emulates the operating characteristics of synchronous generators to achieve voltage and frequency regulation, providing active frequency and voltage support capabilities while effectively increasing the inertia level of new energy units. VSG control has garnered significant attention due to its active support features; however, the factors influencing its voltage support capability are not yet fully understood, necessitating further research on VSG control strategies that balance voltage support with short-circuit current limitations. To address these issues, this paper first analyzes the equivalent impedance of each control stage of grid-forming converters based on VSG control during steady-state operation and establishes an equivalent circuit model of the system. Secondly, based on the system's equivalent circuit, the expression for terminal voltage is derived, quantifying the relationship between terminal voltage, internal electromotive force, and system impedance, and analyzing the factors affecting the voltage support capability of VSG. Subsequently, improvements to VSG control are made considering both current limitation requirements and voltage support capability, proposing adaptive control strategies for virtual impedance and voltage compensation coefficients. Finally, the accuracy of the theoretical analysis and the effectiveness of the proposed strategy are verified using the Matlab/Simulink electromagnetic simulation platform. The analysis results show that reducing virtual impedance, reactive power voltage droop coefficient, or increasing the voltage compensation coefficient can enhance the voltage support capability of VSG. However, decreasing virtual impedance and reactive power voltage droop coefficient reduces the system's equivalent impedance, while increasing the voltage compensation coefficient increases the system's internal electromotive force, thus imposing higher demands on the system's current-limiting capacity. By adopting the proposed adaptive control strategy for virtual impedance and voltage compensation coefficients, virtual impedance can be self-adaptively configured according to the system state, ensuring voltage support capability under the premise of meeting current-limiting requirements. Through theoretical analysis and simulation experiments, the following conclusions can be drawn: (1) When the grid-forming converter system based on VSG control enters a steady state, its various control stages can be represented by equivalent impedance, which characterizes the relationship between terminal voltage, internal electromotive force, and system impedance. (2) The voltage support capability of VSG is related to virtual impedance, reactive power voltage droop coefficient, and voltage compensation coefficient. Reducing the reactive power voltage droop coefficient, decreasing virtual impedance, and adding voltage compensation control to the reactive power loop can all improve voltage support capability. (3) Voltage support capability and short-circuit current limitation of VSG interact. Through adaptive control of virtual impedance and voltage compensation coefficients, short-circuit currents can be fully utilized, maximizing the voltage support capability of VSG without exceeding the short-circuit current limit.
刘思佳, 刘海涛, 张隽, 于思奇, 孙大卫, 邢晶, 高本锋. 基于等效阻抗的虚拟同步机电压支撑影响因素分析与改进控制策略研究[J]. 电工技术学报, 2025, 40(9): 2738-2751.
Liu Sijia, Liu Haitao, Zhang Jun, Yu Siqi, Sun Dawei, Xing Jing, Gao Benfeng. Research on the Analysis of Virtual Synchronous Generator Voltage Support Influence Factors and Improvement Control Strategies Based on Equivalent Impedance. Transactions of China Electrotechnical Society, 2025, 40(9): 2738-2751.
[1] 张智刚, 康重庆. 碳中和目标下构建新型电力系统的挑战与展望[J]. 中国电机工程学报, 2022, 42(8): 2806-2819. Zhang Zhigang, Kang Chongqing.Challenges and prospects for constructing the new-type power system towards a carbon neutrality future[J]. Proceedings of the CSEE, 2022, 42(8): 2806-2819. [2] 谢小荣, 贺静波, 毛航银, 等. “双高”电力系统稳定性的新问题及分类探讨[J]. 中国电机工程学报, 2021, 41(2): 461-475. Xie Xiaorong, He Jingbo, Mao Hangyin, et al.New issues and classification of power system stability with high shares of renewables and power electronics[J]. Proceedings of the CSEE, 2021, 41(2): 461-475. [3] 高洁, 王彤, 赵伟, 等. 提升电力系统安全稳定水平的风电光伏场站主动支撑技术发展及展望综述[J]. 新型电力系统, 2024(2): 201-222. Gao Jie, Wang Tong, Zhao Wei, et al.Review on the development and prospect of active support technologies for wind power and photovoltaic stations to improve the security and stability level of power system[J]. New Type Power Systems, 2024(2): 201-222. [4] 许诘翊, 刘威, 刘树, 等. 电力系统变流器构网控制技术的现状与发展趋势[J]. 电网技术, 2022, 46(9): 3586-3595. Xu Jieyi, Liu Wei, Liu Shu, et al.Current state and development trends of power system converter grid-forming control technology[J]. Power System Technology, 2022, 46(9): 3586-3595. [5] 张宸宇, 杨赟, 袁晓冬, 等. 考虑阻尼和惯性的虚拟同步机建模方法研究[J]. 电力工程技术, 2018, 37(5): 45-49. Zhang Chenyu, Yang Yun, Yuan Xiaodong, et al.Modeling method of virtual synchronous machine considering damping and inertia[J]. Electric Power Engineering Technology, 2018, 37(5): 45-49. [6] 潘子迅, 杨晓峰, 赵锐, 等. 不平衡电网下虚拟同步机的多模式协调策略[J]. 电工技术学报, 2023, 38(16): 4274-4285. Pan Zixun, Yang Xiaofeng, Zhao Rui, et al.Multi-mode coordination control of virtual synchronous generator under unbalanced power grid[J]. Transactions of China Electrotechnical Society, 2023, 38(16): 4274-4285. [7] 刘欣, 郭志博, 贾焦心, 等. 基于序阻抗的虚拟同步发电机并网稳定性分析及虚拟阻抗设计[J]. 电工技术学报, 2023, 38(15): 4130-4146. Liu Xin, Guo Zhibo, Jia Jiaoxin, et al.Stability analysis and virtual impedance design of virtual synchronous machine based on sequence impedance[J]. Transactions of China Electrotechnical Society, 2023, 38(15): 4130-4146. [8] 胡石阳, 刘国荣. 基于虚拟同步机的新能源并网智能控制研究[J]. 电气技术, 2022, 23(10): 10-17. Hu Shiyang, Liu Guorong.Research on intelligent control of new energy grid connection based on virtual synchronous[J]. Electrical Engineering, 2022, 23(10): 10-17. [9] 秦晓辉, 苏丽宁, 迟永宁, 等. 大电网中虚拟同步发电机惯量支撑与一次调频功能定位辨析[J]. 电力系统自动化, 2018, 42(9): 36-43. Qin Xiaohui, Su Lining, Chi Yongning, et al.Functional orientation discrimination of inertia support and primary frequency regulation of virtual synchronous generator in large power grid[J]. Automation of Electric Power Systems, 2018, 42(9): 36-43. [10] 李美依, 黄文焘, 邰能灵, 等. 频率扰动下虚拟同步电机控制型分布式电源自适应惯性控制策略[J]. 电网技术, 2020, 44(4): 1525-1533. Li Meiyi, Huang Wentao, Tai Nengling, et al.Adaptive inertial control strategy for inverter interfaced distributed generator based on virtual synchronous generator under frequency disturbances[J]. Power System Technology, 2020, 44(4): 1525-1533. [11] 韩平平, 陈鹏飞, 丁明, 等. VSG控制下直驱风机惯量支撑能力定量分析[J]. 电网技术, 2025, 49(2): 501-510. Han Pingping, Chen Pengfei, Ding Ming, et al.Quantitative analysis of inertia support capacity of direct drive fan under VSG control[J]. Power Grid Technology, 2025, 49(2): 501-510. [12] 闻章, 姚良忠, 程帆, 等.考虑转子稳定性约束的直驱风机虚拟同步发电机构网频率支撑控制[J/OL]. 电网技术, 2024: 1-10[2024-10-20]. https://doi.org/10.13335/j.1000-3673.pst.2024.0116. Wen Zhang, Yao Liangzhong, Cheng Fan, et al.Network frequency support control of virtual synchronous generator for direct drive fan considering rotor stability constraints[J/OL]. Power Grid Technology, 2024: 1-10[2024-10-20]. https://doi.org/10.13335/j.1000-3673.pst.2024.0116. [13] 王渝红, 宋雨妍, 廖建权, 等. 风电电压主动支撑技术现状与发展趋势[J]. 电网技术, 2023, 47(8): 3193-3205. Wang Yuhong, Song Yuyan, Liao Jianquan, et al.Review and development trends of DFIG-based wind power voltage active support technology[J]. Power System Technology, 2023, 47(8): 3193-3205. [14] 尚磊, 胡家兵, 袁小明, 等. 电网对称故障下虚拟同步发电机建模与改进控制[J]. 中国电机工程学报, 2017, 37(2): 403-412. Shang Lei, Hu Jiabing, Yuan Xiaoming, et al.Modeling and improved control of virtual synchronous generators under symmetrical faults of grid[J]. Proceedings of the CSEE, 2017, 37(2): 403-412. [15] 王雪梅, 王艺博, 刘雨桐, 等. 基于虚拟电抗的主动支撑型新能源机组低电压穿越控制方法[J]. 电网技术, 2022, 46(11): 4435-4444. Wang Xuemei, Wang Yibo, Liu Yutong, et al.Low voltage ride-through control of actively-supported new energy unit based on virtual reactance[J]. Power System Technology, 2022, 46(11): 4435-4444. [16] 张余余, 赵晋斌, 李芬, 等. 基于功角动态补偿的VSG故障穿越方法研究[J]. 电网技术, 2021, 45(9): 3667-3673. Zhang Yuyu, Zhao Jinbin, Li Fen, et al.VSG fault crossing method based on dynamic compensation of power angle[J]. Power System Technology, 2021, 45(9): 3667-3673. [17] 符杨, 陈禹瑾, 季亮, 等. 考虑功率解耦的构网型逆变器的低电压穿越控制策略[J]. 电力系统保护与控制, 2024, 52(15): 1-13. Fu Yang, Chen Yujin, Ji Liang, et al.Low voltage ride-through control strategy of a grid-forming inverter considering power decoupling[J]. Power System Protection and Control, 2024, 52(15): 1-13. [18] 张兴, 战祥对, 吴孟泽, 等. 高渗透率新能源发电并网变流器跟网/构网混合模式控制综述[J]. 电力系统自动化, 2024, 48(21): 1-15. Zhang Xing, Zhan Xiangdui, Wu Mengze, et al.Review on grid-following/grid-forming hybrid mode control for grid-connected converter in high penetration rate of renewable energy generation[J]. Automation of Electric Power Systems, 2024, 48(21): 1-15. [19] 詹长江, 吴恒, 王雄飞, 等. 构网型变流器稳定性研究综述[J]. 中国电机工程学报, 2023, 43(6): 2339-2359. Zhan Changjiang, Wu Heng, Wang Xiongfei, et al.An overview of stability studies of grid-forming voltage source converters[J]. Proceedings of the CSEE, 2023, 43(6): 2339-2359. [20] 杨铭, 曹武, 赵剑锋, 等. 受控电压/电流源型变流器混合多机暂态电压支撑策略[J]. 电工技术学报, 2023, 38(19): 5207-5223, 5240. Yang Ming, Cao Wu, Zhao Jianfeng, et al.Transient voltage support strategy for hybrid multi-converter of controlled voltage/current source converter[J]. Transactions of China Electrotechnical Society, 2023, 38(19): 5207-5223, 5240. [21] Shuai Zhikang, Huang Wen, Shen Chao, et al.Characteristics and restraining method of fast transient inrush fault currents in synchronverters[J]. IEEE Transactions on Industrial Electronics, 2017, 64(9): 7487-7497. [22] Lin Xinchun, Zheng Yun, Liang Zhigang, et al.The suppression of voltage overshoot and oscillation during the fast recovery process from load short-circuit fault for three-phase stand-alone inverter[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2021, 9(1): 858-871. [23] Oureilidis K O, Demoulias C S.A fault clearing method in converter-dominated microgrids with conventional protection means[J]. IEEE Transactions on Power Electronics, 2016, 31(6): 4628-4640. [24] 姜卫同, 胡鹏飞, 尹瑞, 等. 基于虚拟同步机的变流器暂态稳定分析及混合同步控制策略[J]. 电力系统自动化, 2021, 45(22): 124-133. Jiang Weitong, Hu Pengfei, Yin Rui, et al.Transient stability analysis and hybrid synchronization control strategy of converter based on virtual synchronous generator[J]. Automation of Electric Power Systems, 2021, 45(22): 124-133. [25] Paquette A D, Divan D M.Virtual impedance current limiting for inverters in microgrids with synchronous generators[J]. IEEE Transactions on Industry Applications, 2015, 51(2): 1630-1638. [26] Liu Chang, Cai Xu, Li Rui, et al.Optimal short-circuit current control of the grid-forming converter during grid fault condition[J]. IET Renewable Power Generation, 2021, 15(10): 2185-2194. [27] Zhang Yu, Zhang Chen, Yang Renxin, et al.Current-constrained power-angle characterization method for transient stability analysis of grid-forming voltage source converters[J]. IEEE Transactions on Energy Conversion, 2023, 38(2): 1338-1349. [28] 彭放, 高厚磊, 郭一飞, 等. 构网逆变电源故障穿越控制策略及其对保护影响的研究综述[J]. 电网技术, 2024, 48(9): 3673-3685. Peng Fang, Gao Houlei, Guo Yifei, et al.A review of fault ride-through control strategies for grid-connected inverters and their impact on protection[J]. Power System Technology, 2024, 48(9): 3673-3685. [29] 黄萌, 舒思睿, 李锡林, 等. 面向同步稳定性的电力电子并网变流器分析与控制研究综述[J]. 电工技术学报, 2024, 39(19): 5978-5994. Huang Meng, Shu Sirui, Li Xilin, et al.A review of synchronization-stability-oriented analysis and control of power electronic grid-connected converters[J]. Transactions of China Electrotechnical Society, 2024, 39(19): 5978-5994. [30] 温春雪, 黄耀智, 胡长斌, 等. 虚拟同步发电机接口变换器并联运行虚拟阻抗自适应控制[J]. 电工技术学报, 2020, 35(增刊2): 494-502. Wen Chunxue, Huang Yaozhi, Hu Changbin, et al.Adaptive control of virtual impedance in parallel operation of virtual synchronous generator interface converter[J]. Transactions of China Electrotechnical Society, 2020, 35(S2): 494-502. [31] 葛平娟, 肖凡, 涂春鸣, 等. 考虑故障限流的下垂控制型逆变器暂态控制策略[J]. 电工技术学报, 2022, 37(14): 3676-3687. Ge Pingjuan, Xiao Fan, Tu Chunming, et al.Transient control strategy of droop-controlled inverter considering fault current limitation[J]. Transactions of China Electrotechnical Society, 2022, 37(14): 3676-3687. [32] 刘辉, 于思奇, 孙大卫, 等. 构网型变流器控制技术及原理综述[J]. 中国电机工程学报, 2025, 45(1): 277-297. Liu Hui, Yu Siqi, Sun Dawei, et al.Review on control technology and principle of grid-type converter[J]. Proceedings of the CSEE, 2025, 45(1): 277-297. [33] 国家市场监督管理总局, 国家标准化管理委员会. 虚拟同步机第1部分:总则: GB/T 38983.1—2020 [S]. 北京: 中国标准出版社, 2020.
2025, Vol. 40 
