考虑频率耦合效应的并网模块化多电平变流器阻抗建模及稳定性分析  

Impedance Modeling and Stability Analysis of Grid-connected Modular Multilevel Converter Considering Frequency Coupling Effect

作　　者：杜程茂 杜雄[1] 邹小明[1] 唐基超 DU Chengmao;DU Xiong;ZOU Xiaoming;TANG Jichao(State Key Laboratory of Power Transmission Equipment and System Security and New Technology(Chongqing University),Shapingba Distirct,Chongqing 400044,China)

机构地区：[1]输配电装备及系统安全与新技术国家重点实验室(重庆大学),重庆市沙坪坝区400044

出　　处：《中国电机工程学报》2020年第9期2866-2876,共11页Proceedings of the CSEE

基　　金：国家自然科学基金重点项目(51937001);智能电网保护和运行控制国家重点实验室资助(SGNR0000KJJS1907541)。

摘　　要：模块化多电平变流器(modular multilevel converter,MMC)与电网之间的频率耦合效应会影响变流器的阻抗特性,忽略频率耦合效应对变流器并网系统进行稳定性分析可能导致分析结果不准确。该文采用一种考虑频率耦合效应的整体建模方法,将电网阻抗视为MMC交流侧阻抗的一部分,以谐波矩阵描述频率耦合效应,并考虑不对称外环控制的影响建立MMC交流侧等效阻抗模型。仿真验证结果表明,与忽略频率耦合效应的模型相比,采用所建立的等效阻抗模型进行稳定性分析可以获得更准确的分析结果,为MMC并网系统振荡的有效抑制奠定一定理论基础。The frequency coupling effect between the modular multilevel converter(MMC)and the grid affects the impedance characteristics of the system.It is difficult to obtain accurate analysis results by ignoring the frequency coupling effect for stability analysis.An overall modeling method considering the frequency coupling effect was proposed.The grid impedance was regarded as a part of the MMC AC side impedance,the frequency coupling effect was described by the harmonic matrix,and the influence of the asymmetric outer loop control was considered to establish the MMC AC side equivalent impedance model.The simulation results show that compared with the model which ignores the frequency coupling effect,the stability analysis using the established equivalent impedance model can obtain more accurate analysis results,which lays a theoretical foundation for effectively suppressing the oscillation of grid-connected MMC system.

关 键 词：模块化多电平变流器 稳定性分析 频率耦合效应 不对称外环控制 等效阻抗模型 

分 类 号：TM46[电气工程—电器]