适用于电压幅值双极性调控的直接式AC/AC变换器拓扑结构

针对电网中不确定性事件所带来的电压幅值波动问题,提出了一种适用于电压幅值双极性调控的直接式AC/AC变换器拓扑结构。该拓扑是由2个无差分脉冲宽度调制(PWM)型交流斩波桥臂构成的H桥结构,具有输入/输出"共地"、双自由度、双极性调控与无换流问题等特点。详细分析了变换器的拓扑构成、PWM原理,通过正/反极性场景的分析揭示了其工作模式;在参数设计的基础上,研制了变换器原理样机并搭建了动态电压恢复器系统。不同工况下的实验结果表明,所提出的直接式AC/AC变换器能够有效抑制电压幅值波动。

Topology structure of direct AC/AC converter adapted to voltage amplitude bipolar regulation

In order to solve the problem of voltage amplitude fluctuation caused by uncertain events in power grid,a topology structure of direct AC/AC converter adapted to voltage amplitude bipolar regulation is proposed.The topology is an H-bridge structure composed of two non-differential PWM(Pulse Width Modu⁃lation)AC chopper legs.It maintains the characteristics of input and output“common-ground”feature,two degrees of freedom,bipolar regulation and no commutation problem.The composition of topology and PWM principle of the converter are analyzed in detail,and its working mode is revealed through the analysis of the positive-negative polarity scenes.Based on the parameter design,the prototype of the converter is developed and the dynamic voltage restorer system is built.The experimental results under different working conditions show that the proposed direct AC/AC converter can effectively suppress the voltage amplitude fluctuation.