跟网型逆变器同步稳定性分析及增强控制方法

doi:10.19595/j.cnki.1000-6753.tces.250588

Abstract
Figure/Table
References
Related Citation (15)

Download: PDF (9579 KB) HTML (1 KB)
Export: BibTeX | EndNote (RIS)

Abstract Renewable energy resources (RESs) such as wind power and photovoltaic power have been developed rapidly and applicated in large scale in recent years. The phase-locked loop (PLL) based grid-following inverters (GFLIs) are widely used to connect RESs to the power system due to their advantages of high efficiency, flexibility and controllability. However, with the continuous increase in penetration of power electronic devices and RESs within the power system, GFLIs are prone to loss synchronous stability under transient events like grid voltage sage, grid short circuit and so on, resulting in disconnection of RESs and threatening the safe and stable operation of the power system. Therefore, it is crucial to study the stability issues of GFLIs under transient events. The analysis results reveal that the PLL poses a negative damping effect, which will decrease GFLI’s synchronous stability during transient events, especially under weak grid condition. To address this issue, a stability control method is proposed in this work to enhance GFLI’s synchronous stability during transient events in weak grid condition.
The basic idea of the proposed stability control method is to reduce the negative damping effect introduced by the PLL. Base on this, a feedback loop that uses the deviation of the angular speed between the PLL and the grid as feedback signal is added to the conventional PLL, thereby reducing the negative damping effect of the PLL. Theoretical analysis shows that the stability control method improves the small-signal stability margin of GFLI, increases the equivalent inertia and damping coefficient of GFLI, and thus enhances system’s synchronous stability. The parameter design principle of the stability control method is given with consideration of different grid conditions.
Simulation and hardware-in-the-loop (HIL) experiment results validate that the proposed stability control method can enhance the stability of GFLI under the conditions of grid voltage sag, sudden changes in grid impedance and grid phase. With the traditional PLL that doesn’t adopt the stability control method, the system losses synchronous stability when grid voltage drops from 1pu to 0.63(pu), grid impedance steps from 1(pu) to 1.58(pu) and grid phase steps 190°. On the contrary, with the stability control method, the GFLI grid-connected system can maintain stability when grid voltage drops to 0.58(pu), grid impedance steps to 1.68(pu) and grid phase steps 200°.
The following conclusions can be drawn through the research presented in this paper: (1) The necessary condition for GFLI grid-connected system to maintain stability during transient events lies in the existence of a post-fault steady-state equilibrium point (SEP), which must satisfy the small-signal stability criterion. (2) The smaller the voltage sage, grid inductance, PLL’s integral coefficient, and the system active current, the greater the system stability. PLL’s proportional coefficient poses dual effects on GFLI’s stability. Within a certain range, increased proportional coefficient can enhance system’s synchronous stability. However, excessive proportional coefficient will induce overspeed angular velocity in the GFLI, even make the system fail to meet the small-signal stability condition, thereby deteriorating system’s stability. (3) The proposed stability control method can not only enhance the small-signal stability margin of GFLI, but also strengthen synchronous stability.

Key words： Renewable energy power generation grid-following inverter phase-locked loop synchronous stability stability control

Received: 11 April 2025

PACS:

TM464

	Service

	E-mail this article
	Add to my bookshelf
	Add to citation manager
	E-mail Alert
	RSS
	Articles by authors
	Wang Pengfei
	Chen Jiawei
	Luo Chao
	Gu Haohan
	Cai Haiqin

Cite this article:

Wang Pengfei,Chen Jiawei,Luo Chao等. Synchronous Stability Analysis and Enhancement Control Method for Grid-Following Inverters[J]. Transactions of China Electrotechnical Society, 2026, 41(7): 2397-2410.

URL:

https://dgjsxb.ces-transaction.com/EN/10.19595/j.cnki.1000-6753.tces.250588 OR https://dgjsxb.ces-transaction.com/EN/Y2026/V41/I7/2397

[1] 曾祥辰, 刘青, 王嘉晨, 等. 弱电网下并网逆变器恒定带宽及稳定裕度的自适应控制策略[J]. 电工技术学报, 2024, 39(9): 2682-2695.
Zeng Xiangchen, Liu Qing, Wang Jiachen, et al.Adaptive control strategy of grid-connected inverters with constant bandwidth and stability margin in weak grids[J]. Transactions of China Electrotechnical Society, 2024, 39(9): 2682-2695.
[2] Zhou Weihua, Mohammed N, Bahrani B.Comprehensive modeling, analysis, and comparison of state-space and admittance models of PLL-based grid-following inverters considering different outer control modes[J]. IEEE Access, 2022, 10: 30109-30146.
[3] 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.
Li Hong, Liang Junyang, Wang Zhenmin, et al.Small signal synchronization stability analysis and improved control strategy for grid following converter[J]. Transactions of China Electrotechnical Society, 2024, 39(12): 3802-3815.
[4] Zhao Jiantao, Huang Meng, Zha Xiaoming.Nonlinear analysis of PLL damping characteristics in weak-grid-tied inverters[J]. IEEE Transactions on Circuits and Systems II: Express Briefs, 2020, 67(11): 2752-2756.
[5] 刘昊, 方天治, 张惠丽, 等. 弱电网下应对复杂稳定性问题的并网逆变器改进电压前馈通路研究[J]. 电工技术学报, 2024, 39(16): 4955-4967.
Liu Hao, Fang Tianzhi, Zhang Huili, et al.Research on an improved voltage feedforward path of grid-connected inverter coping with complex stability issues in weak grid[J]. Transactions of China Electrotechnical Society, 2024, 39(16): 4955-4967.
[6] 张占俊, 李建文, 董耀, 等. 弱电网下多逆变器并网谐振失稳分析方法[J]. 电气技术, 2020, 21(10): 21-28.
Zhang Zhanjun, Li Jianwen, Dong Yao, et al.Method of resonance instability analysis of multiple grid-connected inverters in weak grid[J]. Electrical Engineering, 2020, 21(10): 21-28.
[7] He Xiuqiang, Geng Hua, Xi Jiangbei, et al.Resynchronization analysis and improvement of grid-connected VSCs during grid faults[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2021, 9(1): 438-450.
[8] 李鹏飞, 李霞林, 王成山, 等. 中低压柔性直流配电系统稳定性分析模型与机理研究综述[J]. 电力自动化设备, 2021, 41(5): 3-21.
Li Pengfei, Li Xialin, Wang Chengshan, et al.Review of stability analysis model and mechanism research of medium- and low-voltage flexible DC distribution system[J]. Electric Power Automation Equipment, 2021, 41(5): 3-21.
[9] Zhao Jiantao, Huang Meng, Zha Xiaoming.Nonlinear analysis of PLL damping characteristics in weak-grid-tied inverters[J]. IEEE Transactions on Circuits and Systems II: Express Briefs, 2020, 67(11): 2752-2756.
[10] 胡祺, 付立军, 马凡, 等. 弱电网下基于锁相控制并网变换器小扰动同步稳定分析[J]. 中国电机工程学报, 2021, 41(1): 98-108, 401.
Hu Qi, Fu Lijun, Ma Fan, et al.Small signal synchronizing stability analysis of PLL-based VSC connected to weak AC grid[J]. Proceedings of the CSEE, 2021, 41(1): 98-108, 401.
[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.
Liang Junyang, Li Hong, Song Guojie, et al.Synchronization stability analysis and enhanced control of grid-following converters under multi-timescale control[J]. Transactions of China Electro-technical Society, 2024, 39(22): 7182-7196.
[12] 张梓钦, 朱东海, 马玉梅, 等. 弱电网故障下新能源并网变换器的奇异摄动模型与暂态稳定性分析[J]. 中国电机工程学报, 2023, 43(2): 454-466.
Zhang Ziqin, Zhu Donghai, Ma Yumei, et al.Singular perturbation model and transient stability analysis of grid-connected converter under weak grid faults[J]. Proceedings of the CSEE, 2023, 43(2): 454-466.
[13] Xu Jinming, Ling Zihan, Luo Yunhu, et al.Synchronization stability analysis and parameter design of grid-following inverters considering the interactions of current control and phase-locked loop[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2024, 12(5): 5013-5027.
[14] Wu Chao, Lyu Yashi, Wang Yong, et al.Transient synchronization stability analysis of grid-following converter considering the coupling effect of current loop and phase locked loop[J]. IEEE Transactions on Energy Conversion, 2024, 39(1): 544-554.
[15] 李霞林, 王智, 郭力, 等. 基于最大估计吸引域的VSC接入弱网下的锁相环同步暂态稳定性分析[J]. 中国电机工程学报, 2022, 42(20): 7485-7497.
Li Xialin, Wang Zhi, Guo Li, et al.Transient stability analysis of PLL synchronization in weak-grid-connected VSCs based on the largest estimated domain of attraction[J]. Proceedings of the CSEE, 2022, 42(20): 7485-7497.
[16] Lin Jianheng, Su Mei, Sun Yao, et al.Frequency coupling suppression control strategy for single-phase grid-tied inverters in weak grid[J]. IEEE Transactions on Industrial Electronics, 2022, 69(9): 8926-8938.
[17] 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.
[18] Wu Heng, Wang Xiongfei.Design-oriented transient stability analysis of PLL-synchronized voltage-source converters[J]. IEEE Transactions on Power Electronics, 2020, 35(4): 3573-3589.
[19] Taul M G, Wang Xiongfei, Davari P, et al.An efficient reduced-order model for studying synchronization stability of grid-following converters during grid faults[C]//2019 20th Workshop on Control and Modeling for Power Electronics (COMPEL), Toronto, ON, Canada, 2019: 1-7.
[20] 张宇, 张琛, 蔡旭, 等. 并网变换器的暂态同步稳定性分析: 稳定域估计与镇定控制[J]. 中国电机工程学报, 2022, 42(21): 7871-7884.
Zhang Yu, Zhang Chen, Cai Xu, et al.Transient grid-synchronization stability analysis of grid-tied voltage source converters: stability region estimation and stabilization control[J]. Proceedings of the CSEE, 2022, 42(21): 7871-7884.
[21] Liu C C, Yang Jingxi, Tse C K, et al.Transient synchronization stability of grid-following converters considering nonideal current loop[J]. IEEE Transactions on Power Electronics, 2023, 38(11): 13757-13769.
[22] Yang Jingxi, Tse C K, Huang Meng, et al.Comparison of homoclinic bifurcations between grid-following and grid-forming converters[J]. IEEE Transactions on Industrial Electronics, 2024, 71(5): 4731-4741.
[23] 王继磊, 张兴, 韩峰, 等. 并网逆变器LVRT同步稳定性分析及其优化策略[J]. 太阳能学报, 2024, 45(2): 309-317.
Wang Jilei, Zhang Xing, Han Feng, et al.Synchronous stability analysis and optimization strategy of LVRT for grid-connected inverter[J]. Acta Energiae Solaris Sinica, 2024, 45(2): 309-317.
[24] Mansour M Z, Ravanji M H, Karimi A, et al.Small-signal synchronization stability enhancement of grid-following inverters via a feedback linearization controller[J]. IEEE Transactions on Power Delivery, 2022, 37(5): 4335-4344.
[25] Yang Huoming, Eggers M, Teske P, et al.Comparative stability analysis and improvement of grid-following converters using novel interpretation of linear time-periodic theory[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2022, 10(6): 7049-7061.
[26] Lu Shaoqi, Xu Zheng, Xiao Liang, et al.Evaluation and enhancement of control strategies for VSC stations under weak grid strengths[J]. IEEE Transactions on Power Systems, 2018, 33(2): 1836-1847.
[27] 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, 2024, 39(2): 554-566.
Yang Ming, Yang Zhuo, Li Yulong, et al.A phase-locked loop design method based on impedance remodeling of grid-connected inverter under high permeability[J]. Transactions of China Electrotechnical Society, 2024, 39(2): 554-566.
[28] 于彦雪, 马慧敏, 陈晓光, 等. 弱电网下基于准静态模型的混合控制微电网逆变器同步稳定性研究[J]. 电工技术学报, 2022, 37(1): 152-164.
Yu Yanxue, Ma Huimin, Chen Xiaoguang, et al.Synchronous stability research of inverters in hybrid microgrid based on the quasi-static models under weak grid[J]. Transactions of China Electrotechnical Society, 2022, 37(1): 152-164.
[29] 宋永端. 自动控制原理-下[M]. 北京: 机械工业出版社, 2020.
[30] Zhao Jiantao, Huang Meng, Yan Han, et al.Nonlinear and transient stability analysis of phase-locked loops in grid-connected converters[J]. IEEE Transactions on Power Electronics, 2021, 36(1): 1018-1029.
[31] 国家质量监督检验检疫总局, 中国国家标准化管理委员会. 分布式电源并网技术要求: GB/T 33593—2017[S]. 北京: 中国标准出版社, 2017.