双星型模块组合型多电平变换器的PWM控制策略  

PWM Control Strategies of Double Star-Connected Modular Multilevel Converter

作　　者：杨晓峰[1] 孙浩[1] 支刚[1] 郑琼林[1] 

机构地区：[1]北京交通大学电气工程学院

出　　处：《电力电子》2010年第2期14-19,25,共7页Power Electronics

摘　　要：双星型模块组合型多电平变换器(MMC)具有良好的可扩展性、模块化、故障无损特性,是一种能很好满足未来高压或中压功率变换需求的拓扑。然而,很少文章对其PWM调制策略及参考电压指令生成方法进行详细的分析和讨论。基于MMC的电路结构特点和基本工作原理,本文提出一种优化的载波移相SPWM控制策略和电压控制策略,无需额外的硬件电路,即可实现对MMC功率单元直流电容电压良好的均压控制效果。通过一台5电平三相MMC的仿真结果,详细分析了其动态特性、静态特性,验证了本文控制策略的有效性以及MMC的可行性。A double star-connected modular multi-level converter （MMC）, featured with scalability, modular construction and nondestructive fault behavior, fulfils the demanding requirements for future high-voltage or medium-voltage power conversion without transformers. However, few papers have made explicit discussion on its PWM control strategies and generation of the reference voltage command signals. Based on analysis of the structural characteristics and operating principles of MMC, an optimized cartier phase-shifted SPWM modulation strategy and combination voltage control method were proposed for achieving good harmonic elimination and voltage-balancing of the multiple floating dc capacitors without any external circuit. The static and dynamic characteristics were explained in detail on a five-level three-phase MMC. The effectiveness of the proposed modulation strategy and the feasibility of MMC were verified by the simulation results.

关 键 词：双星型连接 模块化 多电平变换器 载波移相SPWM 均压控制 桥臂电流 功率单元 

分 类 号：TM464[电气工程—电器]