摘要
MMC直流故障电流计算方法是研究柔性直流电网直流故障暂态特性、实现快速故障隔离的核心与关键。首先,针对两种典型MMC故障等效模型,对比分析了二者的拓扑结构和故障时刻等效电容电压变化规律;其次,考虑MMC各桥臂子模块电容电压均衡机制,提出了MMC平均电容的计算方法,在此基础上提出了基于平均电容的MMC直流故障电流计算方法;最后,通过在PSCAD/EMTDC搭建MMC-HVDC模型进行仿真,验证了提出MMC直流故障电流计算方法的准确性和适用性。
The DC fault current calculation method of modular multilevel converter(MMC)is the key to study the DC fault transient characteristics and isolate the fault point rapidly in VSC-HVDC grid.Firstly,aiming at two typical MMC fault equivalent models,the topology and the capacitor voltage characteristics when the fault occurs were compared and analyzed.Secondly,considering the submodules′capacitor voltage balancing mechanism of each MMC arm,the average capacitance calculation method of MMC was proposed,and then the MMC DC fault current calculation method based on average capacitance was proposed.Finally,the MMC-HVDC model was built on PSCAD/EMTDC and the precision and applicability of the DC fault current calculation method was verified.
作者
黄旭
刘轶超
朱汉卿
刘扬
HUANG Xu;LIU Yichao;ZHU Hanqing;LIU Yang(Stage Grid Tianjin Electric Power Company,Tianjin 300171,China;The Key Laboratory of Smart Grid of Ministry of Education(Tianjin University),Tianjin 300072,China)
出处
《电气传动》
2022年第17期46-51,共6页
Electric Drive
关键词
模块化多电平换流器
直流故障电流
故障等效模型
平均电容
modular multilevel converter(MMC)
DC fault current
fault equivalent model
average capacitance
