Analysis and Suppression of Voltage Overshoot in Symmetrical Hybrid Five-level Converter

This paper analyzes the device voltage overshoot in the symmetrical hybrid five-level converter. Owing to the presence of stray inductance, the voltage that the power devices need to withstand during switching operations may exceed their rated values. To address this issue, a device voltage overshoot suppression method suitable for the topology is proposed in this paper. This method suppresses SiC MOSFET voltage overshoot through adjustment of switching speed and the utilization of snubber capacitance, and it employs the design of RC and dual-RCD snubber circuits to suppress Si IGBT voltage overshoot. Simulation and experimental results certificate the effectiveness of the proposed method in suppressing device voltage overshoot.