大功率变流器共模电压产生及抑制研究

通过三相等效电路详细分析了H桥多电平变流器共模电压的产生机理,介绍了共模电压对大功率变流器及变频调速系统的危害;讨论了目前共模电压抑制技术的研究现状,分析了外加滤波装置和改变变流器结构的硬件抑制方法及采用控制策略的软件抑制方法的特点及其不足,为研究新的共模电压抑制策略提供了参考;最后,提出未来大功率变流器共模电压抑制的研究重点:一是兼顾直流电压利用率和谐波含量的最优共模电压抑制方法,二是从本质上找出一种通用于各种拓扑结构的完全消除共模电压的统一算法。

Research of Generating and Suppressing of Common-mode Voltage in High Power Converter

The paper analyzed generating mechanism of CMV of cascade multilevel converter with a three-phase equivalent circuit in details and introduced harms to high power converter and frequency-conversion speed-regulation system caused by CMV. Then it discussed researching situation of suppressing CMV at present and analyzed characteristics and disadvantages of suppressing CMV methods with hardware named adding filtering equipments and changing converter's structure and suppressing CMV method with software named control strategy,so as to provide some reference for researching a new strategy to suppress CMV.At last,it proposed some future research targets of suppressing CMV of high power converters: firstly,it is important to find an optimal suppressing CMV method which can take account of utilization of DC voltage and harmonic content;secondly,it is necessary to find a unified algorithm for completely eliminating CMV which is suitable for all topologies.