Design of A Novel Soft-switching Buck Converter with Passive Snubber for DC Charging Applications

This paper presents the analytical and design method of a passive Minimum Voltage Stress (MVS) soft-sowitching Buck converter with coupled inductors for DC charging applications. Zero Voltage Switching (ZVS) and Zero Current Switching (ZCS) can be realized to ahcieve 97.2% efficiency for a 18kW prototype. The proposed passive soft-switching Buck converter targets at minimized participation of auxiliary components during the power delivery phase, reducing the current magnitude through auxiliary diodes and inductor. Apart from soft-switching charateristics, adoption of interleaving operation and coupled magnetics result in fast load response and low ripple current, along with weight and volume reduction of the entire rectifier system as a whole. Operation principle, design method for passive snubber network and coupled inductor design has been analyzed. Simulaion and experimental results validate the effectiveness of the theoretical analysis.