A High Frequency-Link Secondary-Side Phase-Shifted Full-Range Soft-Switching PWM DC–DC Converter With ZCS Active Rectifier for EV Battery Chargers

A new prototype of a secondary-side phase shift soft-switching PWM dc-dc converter suitable for electric vehicle battery charging systems is presented in this paper. Wide range soft-switching operations are achievable from full load to no load by effectively utilizing the parasitic inductances of the high frequency transformer in the proposed dc-dc converter. In addition, no circulating current occurs in both of the primary and secondary side full-bridge circuits; thereby, the related idling power can be minimized. As a result, high efficiency power conversion can be maintained owing to the full range soft-switching operation and wide range output power and voltage regulations. Its operating principle is presented on the basis of theoretical analysis and simulation results, and the design procedure of the circuit parameters of the proposed dc-dc converter is described. The essential performance and its effectiveness of the proposed dc-dc converter are originally demonstrated from a practical point of view in an experiment using a 1 kW-50 kHz laboratory prototype.