组合多电平式APF直流侧电压平衡控制策略

Combined Multi-level Inverter and DC Side Voltage Balance Control for Active Power Filter

H桥级联式多电平变流器用于有源电力滤波器（APF）时,H桥功率单元直流侧电容电压的平衡是系统的重点,也是难点。通过对应用两电平变流器或H桥级联式多电平变流器的APF的研究,提出了一种更有利于实现多电平APF直流侧电容电压平衡控制的组合式多电平变流器拓扑;以新的多电平拓扑为基础,提出了一种双电压环的直流侧电压控制策略,解决了多电平有源电力滤波器直流侧电压平衡问题。仿真和实验证明,该组合式多电平变流器拓扑是有效实用的,直流侧电容电压平衡控制策略也具有良好的控制效果。

DC side capacitor voltage balance of H-bridge power unit is vital to the system, and is also difficult when the inverter based on cascaded H-bridge multi-level topology is used for active power filter（APF）. In this study, a combined multi-level inverter topology, which is conducive to achieving the voltage balance control of multi-level APF DC side capacitor, is proposed by analyzing the APF with two-level converter or H-bridge cascade multilevel converter. Based on the new multi-level topology, a DC side voltage control strategy with dual voltage loops is proposed for the multi-level APF DC side voltage balance. Simulation and experiment show that both of the proposed combined multi-level converter topology and the DC side capacitor voltage control strategy are effective and applicable.