外环限幅对VSC并网系统大扰动稳定性的影响研究  

Research on the Large Disturbance Stability of Grid-connected VSC System Considering the Limiter Strategy of Outer Loop

作　　者：王一鸣 孙华东 徐式蕴 沈沉[2] 毕经天 刘新元 WANG Yiming;SUN Huadong;XU Shiyun;SHEN Chen;BI Jingtian;LIU Xinyuan(China Electric Power Research Institute,Haidian District,Beijing 100192,China;Department of Electrical Engineering,Tsinghua University,Haidian District,Beijing 100084,China;State Grid Shanxi Electric Power Research Institute,Taiyuan 030001,Shanxi Province,China)

机构地区：[1]中国电力科学研究院有限公司,北京市海淀区100192 [2]清华大学电机工程与应用电子技术系,北京市海淀区100084 [3]国网山西省电力公司电力科学研究院,山西省太原市030001

出　　处：《中国电机工程学报》2023年第23期9114-9126,共13页Proceedings of the CSEE

基　　金：国家电网有限公司总部科技项目:高比例新能源电力系统大扰动稳定特性及失稳判别理论研究(5100-202055389A-0-0-00)。

摘　　要：以电压源型逆变器(voltage source converter,VSC)为并网接口的新能源发电设备在电力系统中的占比日益提高,现有VSC并网系统大扰动稳定性的研究,往往只关注于锁相环及其他控制环节特性,而未考虑非线性限幅环节及其对稳定性的约束作用。针对上述问题,该文以VSC并网系统的外环控制及其限幅环节为研究对象,首先建立以电流分量为状态变量的简化模型,分析控制外环平衡点的存在性;其次,基于Poincaré定理和Lyapunov第二定理证明运行点总于固定切出点脱离限幅约束及其确定性条件,揭示大扰动后含外环限幅VSC并网系统注入电网功率与指令值不一致的机理;再次,提出计及设备安全性和稳定性的限幅策略改进原则,并设计基于C-UCE的外环限幅改进策略;最后,基于实际VSC并网系统算例验证该文改进策略的有效性。The proportion of renewable energy generation with voltage source converter(VSC)as the interface is increasing.The existing researches only focus on the characteristics of the phase-locked loop(PLL)and other control loops while ignoring the influence of nonlinear loops such as limiter on the stability.To fill the gap,the effect of the VSC outer loop and its limiter on the large disturbance stability is of the main interest in this paper.Firstly,a simplified grid-connected VSC system is established to analyze the existence of equilibrium points,which takes the electrical quantity constrained by the limiter as the state variable.Secondly,based on the Poincarétheorem and Lyapunov’s second theorem,the deterministic condition of the fixed point is proved,which is a fixed position away from the outer loop limiter.The mechanism that the actual power is inconsistent with the command value under the large disturbance is revealed.Then,the limiter principle considering safety and stability is proposed,and based on this,the improved limiter strategy is designed.Finally,the analysis results based on the actual model show that a reasonable outer loop limiter can improve the stability of the grid-connected VSC system.

关 键 词：VSC并网系统 大扰动稳定性 外环限幅 固定切出点 改进限幅策略 

分 类 号：TM712[电气工程—电力系统及自动化]