并网VSC的大扰动失稳模式  

Large-disturbance instability patterns of grid-connected VSC

作　　者：邢光正 闵勇[1] 陈磊[1] 汤涌 徐式蕴 王金浩 郑惠萍 XING Guangzheng;MIN Yong;CHEN Lei;TANG Yong;XU Shiyun;WANG Jinhao;ZHENG Huiping(State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment,Department of Electrical Engineering,Tsinghua University,Beijing 100084,China;China Electric Power Research Institute,Beijing 100192,China;State Grid Shanxi Electric Power Research Institute,Taiyuan 030001,China)

机构地区：[1]清华大学电机系电力系统及发电设备安全控制和仿真国家重点实验室,北京100084 [2]中国电力科学研究院有限公司,北京100192 [3]国网山西省电力公司电力科学研究院,山西太原030001

出　　处：《电力自动化设备》2022年第8期47-54,共8页Electric Power Automation Equipment

基　　金：国家电网公司科技项目(5100-202055389A-0-0-00)。

摘　　要：目前并网电压源变换器(VSC)的大扰动稳定研究主要集中于锁相环(PLL)同步稳定问题,缺乏对大扰动失稳模式系统性的研究。基于VSC接入无穷大系统的详细模型,提出了VSC控制环节失稳的定义和判据。发现外环控制、PLL均存在大扰动稳定问题,并存在单调失稳、振荡失稳2种失稳形态。考虑脉宽调制(PWM)饱和后,电流环也可能发生失稳。不同失稳模式下系统稳定边界主要由不稳定极限环、不稳定平衡点的稳定流形以及代表饱和非线性的边界三部分组成。不稳定极限环主要由系统中存在的Hopf分岔产生。若系统工作点靠近Hopf分岔,则稳定边界由不稳定极限环组成,此时系统失稳表现为发散振荡。若工作点远离Hopf分岔,则稳定边界由不稳定平衡点的稳定流形组成,系统表现为单调失稳。通过MATLAB时域仿真对理论分析进行了验证。The current research on the large-disturbance stability of grid-connected VSC(Voltage Source Converter)mainly focuses on the problem of PLL(Phase Locked Loop)synchronization stability,and there is a lack of systematic research on the large-disturbance instability patterns.Based on the detailed model of VSC connected to infinite system,the definition and criterion of VSC control loop instability are proposed.Both the outer loop control and PLL have large disturbance stability problems,and there are two types of instability:monotonous instability and oscillatory instability.Considering the saturation of PWM(Pulse Width Modulation),the current loop may also be unstable.The system stability boundary of different instability patterns consists of three main components,the unstable limit cycle,the stable manifold of UEP(Unstable Equilibrium Point)and the nonlinearity boundary corresponding to the saturation.The unstable limit cycle is mainly induced by Hopf bifurcation in the system.If the operating point of the system is close to the Hopf bifurcation,the stability boundary consists of unstable limit cycle,and the system instability is manifested as divergent oscillations.If the operating point is far from the Hopf bifurcation,the stability boundary consists of stable manifold of the UEP,and the system exhibits monotonous instability.The theoretical analysis is verified through MATLAB time domain simulation.

关 键 词：大扰动稳定 大扰动失稳模式 极限环 稳定边界 PWM饱和 电压源变换器 

分 类 号：TM46[电气工程—电器]