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

This article 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, not only achieving 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. To validate the effectiveness of the proposed structure, a 3-kW and 200-kHz prototype APM with an input range of 360-800 V and an output voltage range of 11.5-15.3 V is built and tested. The achieved peak efficiency is 95.5%, and the power density reaches 8.4 kW/L.