基于阻抗重塑的虚拟同步机次同步振荡抑制方法  

Restraining Method of Subsynchronous Oscillation in Virtual Synchronous Generator Based on Impedance Reshaping

作　　者：杨兴武 鲍一鸣 孟致丞 徐常天 王雅妮 薛花 YANG Xingwu;BAO Yiming;MENG Zhicheng;XU Changtian;WANG Yani;XUE Hua(Department of Electrical Engineering,Shanghai University of Electric Power,Yangpu District,Shanghai 200090,China)

机构地区：[1]上海电力大学电气工程学院,上海市杨浦区200090

出　　处：《中国电机工程学报》2024年第14期5538-5547,I0008,共11页Proceedings of the CSEE

基　　金：国家自然科学基金项目(52177184);上海市科技项目(23010501200)。

摘　　要：虚拟同步机通过模拟转子运动方程从而使电力电子装置具有同步发电机的惯性和阻尼特性。然而,虚拟同步机与串联电容补偿电网连接时易发生次同步振荡。针对该问题,该文首先建立虚拟同步机与串联电容补偿电网的序阻抗模型,其次,采用伯德图分析次同步振荡发生的机理,研究传统有源阻尼方法的局限性。在此基础上,提出一种基于阻抗重塑的虚拟同步机次同步振荡抑制方法。在虚拟同步机阻尼系数的反馈回路中增加阻抗重塑控制器,进而利用伯德图分析改进系统的阻抗特性。该阻抗重塑方法可以减小虚拟同步机与串联电容补偿电网在低频段的阻抗相位差,有效抑制次同步振荡发生。相较于传统的有源阻尼控制方法,所提出的次同步振荡抑制方法可以较好的适应系统运行方式变化,并且不会引起虚拟同步机工作点偏移。最后,通过仿真和实验验证所提方法的有效性。Virtual synchronous generator(VSG)simulates the rotor motion equation to enable power electronic devices to have the inertia and damping characteristics of synchronous generators.However,subsynchronous oscillation is prone to occur when the VSG is connected to the series capacitor compensation power grid.In response to this issue,this article first establishes a sequence impedance model of VSG and series capacitor compensation power grid.Then,the mechanism of subsynchronous oscillation is analyzed using the Bode diagram,and the limitations of traditional active damping methods are studied.On this basis,a restraining method of subsynchronous oscillation in VSG based on impedance reshaping is proposed.An impedance reshaping controller is added to the feedback loop of the VSG damping coefficient,and the impedance characteristics of the proposed system are analyzed using the Bode diagram.This impedance reshaping method can reduce the impedance phase difference between the VSG and the series capacitor compensation power grid in the low frequency range,effectively suppressing the occurrence of subsynchronous oscillation.Compared to traditional active damping control methods,the proposed subsynchronous oscillation suppression method can better adapt to changes in system operation mode and will not cause the virtual synchronous generator working point to shift.Finally,the effectiveness of the proposed method is verified through simulation and experiments.

关 键 词：虚拟同步机 串联电容补偿电网 次同步振荡 有源阻尼控制 阻抗重塑 

分 类 号：TM71[电气工程—电力系统及自动化]