A secondary-side phase-shifted zero voltage and zero current full-range soft-switching PWM DC-DC converter for EV battery chargers

A new prototype of a secondary-side phase shifted (SPS) soft switching PWM dc-dc converter suitable for electric vehicle (EV) battery charging systems is presented in this paper. In the proposed dc-dc converter, soft switching commutations are achievable from full load to no load by utilizing parasitic inductances of the high frequency (HF) transformer. Beside that, no circulating current in both of the primary and secondary side full-bridge circuits, consequently the related idling power can be minimized. The wide soft switching principle is described in details. The essential performance and its practical effectiveness of the proposed dc-dc converter are originally demonstrated in experiments by a 1kW-50 kHz prototype.