Stability Improvement Method of Multi-Machine Distributed PGCI Under Hybrid Asymmetric Control

doi:10.3969/j.issn.1008-0198.2025.02.006

Abstract

Abstract: Aiming at the problem of stability improvement under the interaction between multi-machine distributed photovoltaic grid-connected inverter (PGCI) and grid impedance, a stability improvement method of multi-machine distributed PGCI with hybrid asymmetric control architecture is proposed from the d and q axis control loops of PGCI. Firstly, the small-signal impedance model of single-machine system of PGCI considering DC-side voltage fluctuation is constructed. On this basis, considering the influence of line connection impedance and grid impedance, the multi-input and multi-output impedance matrix model of multi-machine distributed PGCI is derived. Secondly, based on the d and q axis impedance characteristics of the GCI, two types of asymmetric impedance reshaping control methods are proposed, which significantly improve the stability of the single-machine grid-connected system. Meanwhile, by analyzing the influence of d-q axis hybrid asymmetric control on multi-machine PGCI, it is shown that d-q axis hybrid asymmetric control can effectively improve the adaptability of PGCI to grid impedance. Finally, the correctness and effectiveness of the proposed control strategy are verified by simulation.

Key words: photovoltaic grid-connected inverter, multi-machine grid-connected, impedance matrix, dq axis impedance remodeling, stability

CLC Number:

WANG Xiaoyuan, NING Zhihao, GAO Jiayuan, QING Mengqi, XIA Tian, TANG Xingzhu, YI Zhijian. Stability Improvement Method of Multi-Machine Distributed PGCI Under Hybrid Asymmetric Control[J]. Hunan Electric Power, 2025, 45(2): 45-53.

References

[1] 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):461-474.
[2] 刘永奇,陈龙翔,韩小琪. 能源转型下我国新能源替代的关键问题分析[J]. 中国电机工程学报,2022,42(2):515-524.
[3] 孙秋野,隋政麒,王睿,等.“双高”电力系统非经典稳定性分析[J]. 中国电机工程学报,2023,43(增刊1):1-13.
[4] 谢小荣,刘华坤,贺静波,等. 电力系统新型振荡问题浅析[J]. 中国电机工程学报,2018,38(10):2821-2828,3133.
[5] 司文佳,陈俊儒,张成林,等.直流电压控制对跟网型并网变换器的影响机理[J/OL].上海交通大学学报,1-19.(2023-10-25)[2024-11-01].https://doi.org/10.16183/j.cnki.jsjtu.2023.321.
[6] 赵玉静,牟倩颖,宾子君,等. 考虑直流侧动态的跟网型变换器稳定性分析[J]. 电力工程技术,2024,43(3):12-22.
[7] 姚文峰,邱建,张野,等. 跟网型逆变器附加频率控制方法与参数分析[J]. 电力系统及其自动化学报,2024,36(10):143-150.
[8] 张烨,田慕琴,宋建成,等. 弱电网下计及锁相环影响的并网逆变器输出阻抗重塑[J]. 高电压技术,2021,47(11):4033-4044.
[9] 李红,梁军杨,王振民,等. 跟网型变换器的小扰动同步稳定机理分析与致稳控制[J]. 电工技术学报,2024,39(12):3802-3815.
[10] YANG D S,WANG X F,LIU F C,et al.Symmetrical PLL for SISO impedance modeling and enhanced stability in weak grids[J]. IEEE Transactions on Power Electronics,2019,35(2):1473-1483.
[11] 梁军杨,李红,宋国杰,等. 多时间尺度控制下跟网型变换器的同步稳定性分析与改进控制[J]. 电工技术学报,2024,39(22):7182-7196.
[12] 叶伟豪,郭强,赵兵,等. 弱电网下电压源型逆变器多机系统交互影响及失稳机理研究[J].电网技术,2023,47(11):4377-4385.
[13] PENG X H,YANG H G.Stability analysis of multi-paralleled grid-connected inverters including distribution parameter characteristics of transmission lines[J]. CSEE Journal of Power and Energy Systems,2021,7(1):93-104.
[14] GHADI M A,KAMALINEJAD K,RAZI R,et al.Stability analysis and enhancement of parallel grid-connected inverters with LCL filter in a weak grid[C]//2022 12th Smart Grid Conference(SGC). Kerman,Iran. Islamic Republic of IEEE,2022:1-6.
[15] LI Y,SHUAI Z K,LIU X,et al.Stability analysis and location optimization method for multiconverter power systems based on nodal admittance matrix[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics,2021,9(1):529-538.
[16] 刘偲艳. 不平衡电网下并网逆变器多目标模型预测功率控制[J]. 电气工程学报,2023,18(1):77-85.
[17] LI Y L,GE Y,LIN Q Y,et al.Adaptive parameter optimization based on LCL single-phase grid-connected inverter[C]//2023 35th Chinese Control and Decision Conference (CCDC). Yichang,China. IEEE,2023:307-312.
[18] ZHENG J F,WANG Q,LI Y F,et al.Proportional resonance control application for photovoltaic grid-connected inverters[C]//2023 5th Asia Energy and Electrical Engineering Symposium(AEEES). Chengdu,China. IEEE,2023:935-940.
[19] XU R,WU S R,XIANG S Q,et al.An optimization method of virtual synchronous generators parameter design based on power equivalent model[C]//2022 5th International Conference on Energy,Electrical and Power Engineering(CEEPE).Chongqing,China. IEEE,2022:663-669.
[20] CESPEDES M,SUN J. Adaptive control of grid-connected inverters based on online grid impedance measurements[J]. IEEE Transactions on Sustainable Energy,2014,5(2):516-523.
[21] ZHU D H,ZHOU S Y,ZOU X D,et al.Improved design of PLL controller for LCL-type grid-connected converter in weak grid[J]. IEEE Transactions on Power Electronics,2020,35(5):4715-4727.
[22] 邓紫妮,粟梅,孙尧,等. 面向串联补偿三相并网逆变器的模拟阻抗控制策略[J]. 湖南电力,2023,43(5):31-37.