摘要
多电平PWM整流器具有功率因数可控、能量双向流动等优点,在电机高性能控制场合广受关注。而模块化多电平变换器(MMC)以结构模块化、不需要输入变压器以及易于扩展等优点,成为近年来研究的热点。本文针对一种新型模块化五电平PWM整流器展开研究,与传统MMC不同的是,新型MMC拓扑通过引入一个中间单元,使得输出相同电平数的情况下级联的单元数量更少。该五电平PWM整流控制系统可分为整流控制单元和PWM控制单元两部分,整流控制单元采用电压定向矢量控制实现母线电压稳定和单位输入功率因数控制;PWM控制单元采用载波层叠PWM方法,根据电容电压高低和电流方向选择合适的单元工作在充电或放电模式,以实现电容电压动态平衡控制。该控制方法可适用于任意单元级联和任意电平数。设计了一台三相五电平的实验样机并对上述控制方法进行了实验验证。
Multilevel PWM rectifier is featured with unity power factor,bidirectional power flow and suitable for high voltage high power applications.Modular multilevel converter（MMC） is a highly attractive multilevel converter topology for medium and high voltage applications during recent years for its high modularity,transformer-less feature and possibility to be extended to higher levels.This paper presents a five-level PWM rectifier based on a new MMC topology which needs fewer cells than conventional MMC.Voltage oriented control is used to control the bus voltage and input power factor,and voltage balancing control is realized by selecting proper basic cells operating at different modes according to their instantaneous capacitor voltages and the bridge current direction.The proposed method can be used for any number of basic cells in series and any voltage levels.The validity of the proposed method is verified by experimental results with a three-phase five-level PWM rectifier.
出处
《电工技术学报》
EI
CSCD
北大核心
2011年第5期34-38,共5页
Transactions of China Electrotechnical Society
