抑制级联H 桥变换器共模电压的简化SVPWM 策略

Simplified SVPWM Strategy for Suppressing Common-mode Voltage of CascadedH-bridge Converters

为解决传统空间矢量调制策略难以拓展至高电平数级联H桥多电平变换器,以及抑制级联H桥多电平变换器调制策略实现过程中产生的共模电压的问题,本文提出一种简化空间矢量调制策略。该策略基于α'β'坐标系,通过判断空间矢量所处区域,得出其边界开关状态,再引入修正参数K对边界开关状态进行修正,以此提高策略的快速性并完成共模电压抑制。仿真和实验结果表明该策略实现简单,可以将级联H桥多电平变换器共模电压抑制在最小变化范围内。

To solve the problem that the traditional space vector pulse width modulation(SVPWM)strategy is difficult to be extended to high-level cascaded H-bridge multilevel converter(CHBMC)while suppressing the common-mode voltage generated during the implementation of the CHBMC modulation strategy,a simplified SVPWM strategy based on theα'β'coordinate system is proposed.The boundary switching state is derived by judging the area where the space vector is lo⁃cated.Then,a correction parameter K is introduced to correct the boundary switching state so as to improve the speed of the strategy and realize the common-mode voltage suppression.Simulation and experimental results show that the pro⁃posed strategy is simple to implement and can suppress the CHBMC common-mode voltage within a minimum range.