在对级联式H桥多电平整流器的电路拓扑、工作原理进行简要叙述后,以相量图的方式对整流器交流侧稳态工作情况进行分析,指出在负载不平衡情况下保证电容电压平衡的条件.根据此条件设计了一种便于实现和扩展的电容电压平衡控制策略.该控制策略在平衡直流侧输出电压的同时,可实现交流侧单位功率因数.仿真和实验结果验证了所提出控制策略的有效性.
The phasor diagram of steady state cascaded H-bridge multilevel rectifier is described as the capacitors' voltage balancing condition while the loads connected to each H-bridge may differ.A control strategy easy to implement and extend is proposed to control the DC side capacitors' voltage of the rectifier as well as the unity power factor. Both the simulation and experimental results verify the validity of the proposed control strategy.