基于MMC的背靠背异步联网系统宽频带频率耦合阻抗模型及小信号稳定性分析  

Frequency-coupling Impedance Model and Small-signal Stability Analysis of the MMC-based Back-to-back Asynchronous Grid Interconnection System

作　　者：赵崇滨 姜齐荣[1] 冯海全 王鹏[2] 刘芮彤 ZHAO Chongbin;JIANG Qirong;FENG Haiquan;WANG Peng;LIU Ruitong(State Key Lab of Control and Simulation of Power Systems and Generation Equipment(Dept.of Electrical Engineering,Tsinghua University),Haidian District,Beijing 100084,China;State Grid Beijing Electric Power Company,Xicheng District,Beijing 100031,China;Electric Power Research Institute of State Grid Liaoning Electric Power Supply Co.,Ltd.,Shenyang 110006,Liaoning Province,China)

机构地区：[1]电力系统及发设备控制与仿真国家重点实验室(清华大学电机系),北京市海淀区100084 [2]国网北京市电力公司,北京市西城区100031 [3]国网辽宁省电力有限公司电力科学研究院,辽宁省沈阳市110006

出　　处：《中国电机工程学报》2023年第10期3691-3704,共14页Proceedings of the CSEE

基　　金：国家电网有限公司科技项目(5100-202199515A-0-5-ZN)。

摘　　要：背靠背变流器的稳定性分析是保障电力电子化新型电力系统安全可靠运行的重要基础。该文建立详细模型,研究了基于模块化多电平变流器三相对称背靠背异步联网系统的小信号稳定性。首先提出一种系统频域稳态分析方法并使用牛顿-拉夫逊迭代快速求解多谐波变量。进而基于多谐波线性化法,建立充分计及频率耦合效应的系统交/直流阻抗模型,对比扫频结果证实其宽频带范围的精确性。最后,应用广义Nyquist判据解释小信号失稳工况,体现了包含两端变流器动态的理论模型的必要性,并讨论了交/直流互联端口判据的联系。The stability analysis of the back-to-back converter is the fundamental basis of safe and reliable operation for the power electronized new-type power system.This paper establishes the detailed model and studies the small-signal stability of the three-phase symmetrical back-to-back asynchronous grid-connected system based on the modular multilevel converter.First,a frequency-domain algorithm is proposed to fast solve the steady multiharmonic variables using Newton-Raphson iteration.Then,an impedance model based on the multiharmonic linearization is established fully considering the frequency-coupling effect,whose accuracy is verified by comparing with the frequency scans over the wideband.Finally,the generalized Nyquist criterion is applied to explain the small-signal unstable cases,which reflects the necessity of theoretical models including the converter dynamics of both ends.Discussions are also given on the relations between stability criteria on AC/DC interconnection ports.

关 键 词：背靠背系统 频率耦合 频域稳态分析 阻抗模型 模块化多电平变流器 多谐波线性化 

分 类 号：TM712[电气工程—电力系统及自动化]