级联H桥整流器的新型直流电压与无功平衡控制策略

A Novel DC Voltage and Reactive Power Balance Control Strategy for Cascaded H Bridge Rectifier

为解决级联H桥整流器(cascaded H bridge rectifier,CHBR)的直流侧电压不平衡问题,实现各H桥直流端电压和无功平衡,消除电压平衡控制器与基本双闭环控制器之间的耦合效应,该文提出一种新型的直流侧电压与无功平衡的控制策略。该方法通过对有功和无功占空比按一定关系同时进行修正来实现电压与无功平衡的控制,即使在负载不平衡情况下也能维持直流侧电压和各H桥无功平衡,消除了基本双闭环控制器与电压平衡器之间的耦合效应。同时,分析加入电压平衡控制器的系统稳定性,并讨论电压平衡控制器的有效范围,最后通过仿真和实验验证该方法的有效性和可行性。

In order to solve the problem of the unbalance of cascaded H bridge rectifier （CHBR） dc voltage, realize the balance of the H bridge dc voltage and reactive power, and eliminate the coupling effect between the voltage balance controller and the basic double-loop controller, a new kind of control strategy which consists of dc voltage and reactive power balance was proposed. The method was achieved by amending active duty cycle and reactive duty cycle on the basis of certain relationship, which could also balance the voltage of the dc and the reactive power balance H bridge even under the condition of unbalanced load and could eliminate the coupling effect between the basic double-loop controller and the voltage balance controller at the same time. The paper also analyzed the stability of the system with the proposed balanced controller and discussed its effective range. At last, the simulation and experiments verified the feasibility of the method.