In response to the problems of reverse current and voltage spikes in the traditional power switch diode (PSD)multilevel inverter topology, this paper proposes a symmetrical bidirectional PSD multilevel inverter topology. By in-creasing the reverse current return path, this topology can not only solve the reverse current and voltage spike problems in the traditional PSD topology, but also improve the performances in using the number of power devices, and has ad-vantages in terms of total blocking voltage and switching losses. In order to control the direction of reverse current during inverter operation, this paper analyzes the switching state of symmetric bidirectional cascaded multilevel inverters and proposes a suitable unipolar LS-PWM modulation strategy. This modulation strategy can reduce inverter switching losses while preventing power backflow. Finally, the effectiveness of the topology and modulation strategy is verified by simula-tion and experimental results.
维普
万方数据