Sub-/super-synchronous oscillation,small signal synchronizing stability,and impedance model analysis of converter-based renewable power generators
LIU Wei1, XIE Xiaorong1, JIANG Qirong1, MAO Hangyin2
1. State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment, Department of Electrical Engineering, Tsinghua University, Beijing 100084, China; 2. Zhejiang Electric Power Corporation, Hangzhou 310007, China
Abstract：Connecting converter-based renewable power generators (RPGs) to the power grid can cause serious sub-/super-synchronous oscillations (SSO).Changes in the operating conditions,grid strengths,and converter control can cause the SSO frequency to gradually approach the fundamental frequency while then leads to low-frequency small-signal synchronizing stability (SSS) oscillations.This paper compares the characteristics of SSO and SSS oscillations using the impedance model (IM)-based method that has been used to analyze SSO and is believed to be useful for analyzing the low-frequency oscillations caused by synchronous instabilities.Then,a mathematical model is used to show the equivalence between the phase-locked loop (PLL) dynamic equation-based method and the IM based method for the same grid-tied voltage source converter (VSC) system as a theoretical foundation for SSS analyses using the IM-based method.Finally,time-domain simulations verify the accuracy of the IM-based method for analyzing SSS oscillations of converter-based RPGs.
刘威, 谢小荣, 姜齐荣, 毛航银. 变流式新能源机组的次/超同步振荡、小扰动同步稳定性与阻抗模型分析[J]. 清华大学学报（自然科学版）, 2022, 62(10): 1706-1714.
LIU Wei, XIE Xiaorong, JIANG Qirong, MAO Hangyin. Sub-/super-synchronous oscillation,small signal synchronizing stability,and impedance model analysis of converter-based renewable power generators. Journal of Tsinghua University(Science and Technology), 2022, 62(10): 1706-1714.
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2022, Vol. 62 
