级联H桥整流器直流侧电压平衡控制策略

A modular strategy for control and voltage balance of cascaded H-bridge rectifier

针对电力电子变压器的重要前置组成部分级联H桥整流器的输出电压平衡问题,提出一种基于模拟控制单元和数字控制单元相结合的电压平衡模块化控制策略。所提控制策略由模拟控制单元和数字控制单元构成,模拟控制单元为双闭环控制,外环为比例积分控制,内环为滞环控制,实现所有H桥单元输出总电压的无误差控制及功率因数校正;数字控制单元通过排序算法实现每个H桥单元输出电压的平衡控制;同时,文中对系统的参数进行了详细的设计。在Matlab/Simulink中搭建了5个H桥单元、十一阶的级联H桥整流器,对文中所提出的控制策略进行了仿真,仿真结果验证了所提控制策略的有效性。

Aiming at the problem of output voltage balance of cascaded H-bridge rectifier,which is an important front-end component of power electronic transformer,a modular control strategy based on the combination of analog control unit and digital control unit is proposed. The proposed control strategy is composed of analog control unit and digital control unit. The analog control unit is double closed-loop control. In order to realize the error free control and power factor correction of the total output voltage of all H-bridge units,the outer loop is proportional integral control,and the inner loop is hysteresis control.The digital control unit realizes the balance control of output voltage of each H-bridge unit through the sorting algorithm. The parameters of the system are designed in detail. Five H-bridge units and eleven order cascaded H-bridge rectifier are built in Matlab/Simulink. The simulation experiment verify the effectiveness of the proposed control strategy.