An All-in-one Magnetic Structure for Entire ZVS Range Auxiliary Power Module in Electrical Vehicles

This paper proposes an all-in-one magnetic structure that integrates a leakage inductor, two filter inductors, and a transformer in the phase shift full bridge (PSFB) current doubler converter for the auxiliary power module (APM). The proposed integration technique significantly reduces the number of magnetic components, achieving not only a 17.5% reduction in the magnetic volume and a 26% reduction in the magnetic loss but also simplifying the manufacturing processes. Considering the coupling effect in the proposed integrated structure, the zero voltage switching (ZVS) energy is increased. An optimized coupling coefficient is proposed to cover the entire ZVS range, considering the increase in RMS current associated with an elevated coupling coefficient. In order to validate the effectiveness of the proposed structure, a 3-kW, 200kHz prototype APM with an input range of 360V-800V and an output voltage range of 11.5V-15.3V is built and tested. The achieved peak efficiency is 95.5%, and the power density reaches 8.4kW/L.