模块化多电平换流器环流抑制控制器设计  

Design of Circulating Current Suppressing Controllers for Modular Multilevel Converter

作　　者：屠卿瑞[1] 徐政[1] 管敏渊[1] 郑翔[1] 张静[2] 

机构地区：[1]浙江大学电气工程学院,浙江省杭州市310027 [2]浙江电力调度通信中心,浙江省杭州市310007

出　　处：《电力系统自动化》2010年第18期57-61,83,共6页Automation of Electric Power Systems

摘　　要：为抑制模块化多电平换流器(modular multilevel converter,MMC)内部的三相环流,在MMC内部数学模型的基础上,采用二倍频负序旋转坐标变换将换流器内部的三相环流分解为2个直流分量,并设计了相应的环流抑制控制器(circulating current suppressing controller,CCSC),从而消除了桥臂电流中的环流分量,大大减小了桥臂电流的畸变程度,使其更逼近正弦波。最后通过PSCAD/EMTDC搭建了包含该附加控制器的MMC仿真模型,结果证明所提出的控制方法可以在不用增大桥臂电抗值的情况下,有效地抑制换流器的内部环流,同时不会对MMC外部输出的交流电压和电流产生负面影响。A circulating current suppressing controller（CCSC）is designed to eliminate the inner balancing currents in modular multilevel converter（MMC）.The CCSC uses the inner mathematical model of MMC through a double fundamental frequency negative sequence rotational frame to decompose the three-phase alternative circulating currents to two DC components.The designed CCSC can minimize the distortion degree of the arm current significantly such that the arm current can closely approximate the fundamental sine wave.Simulation results based on PSCAD/EMTDC show that the CCSC can suppress the inner circulating current of MMC efficiently without increasing the arm reactance.It is also shown that this additional controller doesn＇t affect the AC side dynamics of MMC.

关 键 词：模块化多电平换流器 环流抑制控制器 二倍频负序旋转坐标变换 

分 类 号：TM46[电气工程—电器]