Stability Analysis and Improved Strategy of Multi-Inverter Grid-Connected in Weak Grid

Shicong ZHANG, Yonghai XU, Shun TAO, Zhi ZHANG

South Power Sys Technol ›› 2026, Vol. 20 ›› Issue (3) : 19-31.

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South Power Sys Technol ›› 2026, Vol. 20 ›› Issue (3) : 19-31. DOI: 10.13648/j.cnki.issn1674-0629.2026.03.003
DC Transmission & Power Electronic Technology

Stability Analysis and Improved Strategy of Multi-Inverter Grid-Connected in Weak Grid

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Abstract

In weak grid environments, the larger grid impedance enhances the coupling between the grid and each inverter in a multi-inverter parallel system, resulting in decreased system stability or even instability. To address this, a strategy for improving the stability of multi-inverter grid-connected systems under weak grid conditions is proposed. Firstly, Norton equivalent models for single and multiple grid-connected inverters in weak grids are established. Secondly, from the perspective of grid-connected current stability, the stability criterion for the multi-inverter system is decoupled into that of a single-inverter system based on the concept of equivalent grid impedance, clarifying the mechanism behind the reduced system stability in weak grids. Subsequently, an improved control strategy to enhance the stability of the multi-inverter system is proposed, which increases the stability margin of grid-connected inverters by introducing an all-pass filter into the grid voltage feedforward loop and combines a harmonic controller to improve the system's ability to suppress background harmonics. Finally, simulation analysis verifies that the proposed strategy effectively enhances the stability of multi-inverter grid-connected systems under weak grid conditions.

Key words

weak grid / grid-connected inverter / stability / grid voltage feedforward / background harmonics

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Shicong ZHANG , Yonghai XU , Shun TAO , et al. Stability Analysis and Improved Strategy of Multi-Inverter Grid-Connected in Weak Grid[J]. Southern Power System Technology. 2026, 20(3): 19-31 https://doi.org/10.13648/j.cnki.issn1674-0629.2026.03.003

References

[1]
杨明, 杨倬, 李玉龙, 等. 高渗透率下基于并网逆变器阻抗重塑的锁相环设计方法[J]. 电工技术学报202439(2): 554 - 566.
YANG Ming YANG Zhuo LI Yulong, et al. A new phase-locked loop design method based on impedance remodeling of grid-connected inverter under high permeability[J]. Transactions of China Electrotechnical Society202439(2): 554 - 566.
[2]
王静茹, 张福民, 李占凯, 等. 弱电网下电压源型逆变器锁相环的改进[J].电测与仪表202259(3): 187 - 194.
WANG Jingru ZHANG Fumin LI Zhankai, et al. Improvement of phase locked loop of voltage source converter in weak grid[J]. Electrical Measurement & Instrumentation202259(3): 187 - 194.
[3]
苏寅生,刘蔚,张野,等.面向高比例新能源并网的多智能体协同自动发电控制算法[J].高压电器202561(5):80 - 92.
SU Yinsheng LIU Wei ZHANG Ye,et al. Multi-agent-cooperative automatic power generation control algorithm for high proportion of new energy grid connection[J].High Voltage Apparatus202561(5):80 - 92.
[4]
吴应双,刘蔚,刘明顺,等.规模化新能源接入电网下的多区域协同算法[J].南方电网技术202519(9):174 - 188.
WU Yingshuang LIU Wei LIU Mingshun,et al.Multi-area cooperative algorithm under large-scale new energy access to power grid[J].Southern Power System Technology202519(9):174 - 188.
[5]
汪春江, 孙建军, 宫金武, 等. 直驱风机机网侧变流器统一建模及其弱电网下稳定性研究[J]. 电测与仪表202259(10): 87 - 92.
WANG Chunjiang SUN Jianjun GONG Jinwu, et al. Unified modeling of generator-side and grid-side converter in direct-drive wind turbines and stability analysis under weak grid[J]. Electrical Measurement & Instrumentation202259(10): 87 - 92.
[6]
安军, 乔雪婧, 王玉鹏. 考虑锁相环影响的多逆变器并联接入弱电网稳定性分析[J]. 电测与仪表202158(8): 146 - 153.
AN Jun QIAO Xuejing WANG Yupeng. Stability analysis of multi-inverter parallel access to weak power grid considering the influence of phase-locked loop[J]. Electrical Measurement & Instrumentation202158(8): 146 - 153.
[7]
张旸, 陈新, 王昀, 等. 弱电网下并网逆变器的阻抗相角动态制方法[J] .电工技术学报201732(1): 97 - 106.
ZHANG Yang CHEN Xin WANG Yun, et al. Impedance-Phased dynamic control method of grid-connected inverters under weak grid condition[J]. Transactions of China Electrotechnical Society201732(1): 97 - 106.
[8]
邹常跃, 刘邦银, 段善旭, 等. 并网逆变器中数字控制延时对系统稳定性的影响及其优化设计[J]. 中国电机工程学报201535(2): 411-417.
ZOU Changyue LIU Bangyin DUAN Shanxu, et al. Influence of delay on system stability and its optimization in grid-connected inverters[J]. Proceedings of the CSEE201535(2): 411-417.
[9]
WANG Y CHEN Z WANG X, et al. An estimator-based distributed voltage-predictive control strategy for AC islanded microgrids[J]. IEEE Transactions on Power Electronics201530(7): 3934 - 3951.
[10]
曾麟, 单周平, 陈宏, 等. 基于粒子群算法的逆变器侧电流反馈的LCL滤波器优化设计[J]. 南方电网技术201913(2): 59 - 65.
ZENG Lin SHAN Zhouping CHEN Hong, et al. Optimal design of LCL filter with inverter-side current feedback based on particle swarm algorithm[J]. Southern Power System Technology201913(2): 59 - 65.
[11]
苗丽芳, 王乐媛, 曹斌, 等. 弱电网下电网电压前馈控制分布式逆变系统的谐振阻尼特性分析[J]. 高电压技术202046(10): 3521 - 3532.
MIAO Lifang WANG Leyuan CAO Bin, et al. Resonance damping characteristic analysis of distributed inverter-based system with grid voltage feed-forward control in weak grid[J]. High Voltage Engineering202046(10): 3521 - 3532.
[12]
张声淇, 陈冬冬, 洪卫东, 等. LCL型并网逆变器有源阻尼叠加的控制策略[J]. 南方电网技术202418(11): 1 - 12,47.
ZHANG Shengqi CHEN Dongdong HONG Weidong, et al. Control strategy of active damping superposition for LCL grid-connected inverter[J]. Southern Power System Technology202418(11): 1 - 12,47.
[13]
郑晨, 周林, 解宝, 等. 基于相位裕度补偿的大型光伏电站谐波谐振抑制策略[J]. 电工技术学报201631(19): 85 - 96.
ZHENG Chen ZHOU Lin XIE Bao, et al. The harmonic resonance suppression strategy of large-scale photovoltaic plants based on phase margin compensation[J]. Transactions of China Electrotechnical Society201631(19): 85 - 96.
[14]
陈林, 徐永海, 王天泽, 等. 弱电网下计及背景谐波的多并网逆变器阻抗重塑谐振抑制方法[J]. 电力系统保护与控制202452(1): 59 - 72.
CHEN Lin XU Yonghai WANG Tianze, et al. Resonance suppression method for multiple grid-connected inverters with impedance remodeling with background harmonics under weak power grid[J]. Power System Protection and Control202452(1): 59 - 72.
[15]
范路, 李彦哲. 弱电网下提高并网逆变器稳定性的相角方法[J]. 电力电子技术201852(4): 46 - 50.
FAN Lu LI Yanzhe. Phase angle method to increase inverter stability in weak grid impedance[J]. Power Electronics201852(4):46 - 50.
[16]
王渝红, 叶葳, 宋瑞华, 等. 基于阻抗分析法的三相LCL型并网逆变器附加有源阻尼设计[J]. 高电压技术202147(8): 2645 - 2654.
WANG Yuhong YE Wei SONG Ruihua, et al. Short-term wind power forecast based on the radial basis function neural network[J]. High Voltage Engnieering202147(8): 2645 - 2654.
[17]
李强, 孙鹏菊, 董光德, 等. 基于模态分析的多逆变器系统串并联谐振特性分析[J]. 中国电机工程学报202444(13): 5269 - 5281.
LI Qiang SUN Pengju DONG Guangde, et al. Series-parallel resonance analysis of multi-inverter system based on modal analysis[J]. Proceedings of the CSEE202444(13): 5269 - 5281.
[18]
房国振, 陈武晖, 李柯江, 等. 多逆变器并网系统谐振强度评估及其关键节点阻抗辨识方法[J]. 电网技术202549(5): 1962 - 1971.
FANG Guozhen CHEN Wuhui LI Kejiang, et al. Resonance strength evaluation and key node impedance identification method for multi-inverter grid-connected systems[J]. Power System Technology202549(5): 1962 - 1971.
[19]
李戎, 李建文, 李永刚, 等. 结合特征根及模态分析法的逆变器多机并网系统谐波扰动响应分析[J]. 电工技术学报202439(14): 4519 - 4534.
LI Rong LI Jianwen LI Yonggang, et al. Analysis of harmonic disturbance response of multi-inverter grid-connected system combining characteristic root and modal analysis method[J]. Transactions of China Electrotechnical Society202439(14):4519 - 4534.
[20]
陈博, 曾成碧, 苗虹. 提高并网逆变器在弱电网下稳定性的虚拟阻抗附加相角补偿控制[J]. 电测与仪表202360(2): 132 - 137.
CHEN Bo ZENG Chenbi MIAO Hong. Virtual impendence additional phase angle compensation control to improve the stability of grid-connected inverter in weak grid[J]. Electrical Measurement & Instrumentation202360(2): 132 - 137.
[21]
PENG X YANG H. Impedance-based stability criterion for the stable evaluation of grid-connected inverter systems with distributed parameter lines[J]. CSEE Journal of Power and Energy Systems20239(1): 145 - 157.
[22]
赵铁英, 高宁, 杨杰, 等. 基于PI控制器有源阻尼的并网逆变器自适应改进策略[J]. 太阳能学报202344(5): 152 - 161.
ZHAO Tieying GAO Ning YANG Jie, et al. Adaptive improvement strategy for grid-connected inverter based on active damping of PI controllers[J]. Acta Energiae Solaris Sinica202344(5): 152 - 161.
[23]
刘江, 高淑萍, 孙向东, 等. 弱电网下光伏并网逆变器谐振抑制方法综述[J]. 南方电网技术202418(3) :65 - 71.
LIU Jiang GAO Shuping SUN Xiangdong, et al. Overview of resonance suppression methods for PV grid-connected inverters in weak grid[J]. Southern Power System Technology202418(3): 65 - 71.
[24]
张继勇, 孙宜澎, 杨树德. 一种提高变流器弱电网适应能力的全通前馈方法[J]. 电源学报202321(3): 48 - 55.
ZHANG Jiyong SUN Yipeng YANG Shude. All-pass feedforward method for improving the adaptability of converter to weak grid[J]. Journal of Power Supply202321(3): 48 - 55.
[25]
李志军, 刘洪佶, 张家安, 等. 基于频域无源性的并网逆变器前馈相位补偿策略[J]. 电力系统及其自动化学报202335(4): 132 - 139.
LI Zhijun LIU Hongji ZHANG Jiaan, et al. Frequency-domain passivity based feed-forward phase compensation strategy for grid connected inverter[J]. Proceedings of the CSU-EPSA202335(4): 132 - 139.
[26]
AKHAVAN A MOHAMMADI H R VASQUEZ J C, et al. Passivity-based design of plug-and-play current-controlled grid connected inverters[J]. IEEE Transactions on Power Electronics.202035(2): 2135 - 2150.
[27]
汪颖, 罗代军, 肖先勇, 等. 多逆变器并网下的超高次谐振特性分析[J]. 电力系统自动化202044(1): 192 - 199.
WANG Ying LUO Daijun XIAO Xianyong, et al. Analysis on supraharmonic resonance characteristics with integration of multiple inverters[J]. Automation of Electric Power Systems202044(1): 192 - 199.
[28]
AGORRETA J L BORREGA M LÓPEZ J, et al. Modeling and control of N-paralleled grid-connected inverters with LCL filter coupled due to grid impedance in PV plants[J]. IEEE Transactions on Power Electronics201126(3): 770–785.
[29]
高晓帆, 田书, 常永强. 一种新的大型光伏并网系统稳定性分析方法[J]. 电力系统保护与控制202048(1): 26 - 32.
GAO Xiaofan TIAN Shu CHANG Yongqiang. A novel stability analysis method for large-scale photovoltaic system[J]. Power System Protection and Control202048(1): 26 - 32.
[30]
王毅, 高爱杰, 胡楠, 等. 多并网逆变器并联运行的谐振抑制策略[J]. 南方电网技术202216(5): 87 - 96.
WANG Yi GAO Aijie HU Nan, et al. Resonance suppression strategy for multi-parallel grid-connected inverters[J]. Southern Power System Technology202216(5): 87 - 96.
[31]
WANG J SUN P LI B, et al. Analysis of Current Resonance characteristics of multiple grid-connected inverters[C]//2018 IEEE International Power Electronics and Application Conference and Exposition (PEAC), November 4 - 7, 2018, Shenzhen, China. New York: IEEE,2018: 1 - 6.
[32]
FANG T SHEN S JIN Y, et al. Robustness investigation of multi-inverter paralleled grid-connected system with LCL-Filter based on the grid-impedance allocation mechanism[J]. IEEE Transactions on Power Electronics202136(12): 14508 - 14524.
[33]
屠一鸣, 刘进军, 刘增, 等. 基于阻抗的数字延时对单电流环控制型并网逆变器稳定性影响的分析[J]. 电源学报202018(2): 63 - 72.
TU Yiming LIU Jinjun LIU Zeng, et al. Impedance-based analysis of influences of digital control delay on the stability of single current loop-controlled grid-tied inverter[J]. Journal of Power Supply202018(2): 63 - 72.
[34]
洪芦诚, 徐佳裕, 唐润悦, 等. 三相LCL型逆变器序阻抗简化建模方法及并网稳定性分析[J]. 电力系统自动化202347(7): 150 - 157.
HONG Lucheng XU Jiayu TANG Runyue, et al. Simplified modeling method of sequence impedance and grid-connected stability analysis for three-phase LCL inverter[J]. Automation of Electric Power Systems202347(7): 150 - 157.
[35]
李建文, 阮筱菲, 李永刚, 等. 弱电网下多并网逆变器谐振失稳研究综述[J]. 现代电力202037(2): 187 - 196.
LI Jianwen RUAN Xiaofei LI Yonggang, et al. An overview on resonance instability of multiple grid-connected inverters in weak grid[J]. Modern Electric Power202037(2): 187 - 196.
[36]
张成, 赵涛, 朱爱华, 等. 提高弱电网下并网逆变器稳定性的复合补偿策略[J]. 智慧电力202149(5): 42 - 47,76.
ZHANG Chen ZHAO Tao ZHU Aihua, et al. Composite compensation strategy for improving stability of grid connected inverter in weak current network[J]. Smart Power202149(5): 42 - 47,76.
[37]
李志军, 张俊杰, 贾杨. 基于自适应有源阻尼的宽频域谐振抑制器[J]. 南方电网技术202418(10): 95 - 106,160.
LI Zhijun ZHANG Junjie JIA Yang, et al. Wide band resonance suppressor based on adaptive active damping[J]. Southern Power System Technology202418(10): 95 - 106,160.

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the National Natural Science Foundation of China(52377101)
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