Design and implementation of a novel auxiliary network based ZVS DC/DC converter topology with MPWM: an application to electric vehicle battery charging

The DC/DC converter stage has a significant role in the on-board electric vehicle (EV) battery charger. This study proposes a zero voltage switching (ZVS) full-bridge DC/DC converter (FBDC) for efficient power conversion with minimal power loss. The simplified auxiliary circuit-based FBDC consolidate the modified pulse width modulation (MPWM) gating technique for DC/DC conversion stage according to battery profile of the EV. The proposed MPWM can minimise the conduction and switching losses in comparison to the previously proposed converter configuration using conventional phase shift modulation (PSM) gating technique. The size of auxiliary inductance required is reduced with MPWM in comparison to conventional FBDC auxiliary inductance with PSM gating technique. Design and implementation of proposed ZVS FBDC with MPWM are discussed for a 500 W, 80 kHz laboratory prototype and experimental results are presented to validate the design and performance of the proposed converter.