层叠式多单元逆变器浮动电容器电压平衡控制方法

Balancing floating capacitance voltages in the stacked multicell converter

层叠式多单元逆变器是近年来提出的一种新的多重拓扑结构的逆变器,非常适用于高性能、高电压系统中。但其存在浮动电容器的电压失配问题,尤其在低开关频率时尤为显著。基于层叠式多单元逆变器(SMC)电路,提出了一种平衡浮动电容器电压的控制方法,以保证开关电压的均匀分布,同时改进输出电压和电流频谱。采用正弦脉冲模拟技术被用于证实了控制方法的可行性。

The stacked multicell converter is a new multilevel topology developed in recent years, which is suitable for high-voltage and high-power applications. But the unbalance of the floating capacitor voltage can be a problem, especially at low switching frequencies. This paper addresses a control strategy to balance the voltage across the floating capacitors to ensure the even sharing of the voltage stresses in the switching devices and improve the output voltage and current spectrum. Sinusoidal pulse width modulation technique is used to confirm the feasibility of the control methods.