OBC and APM Integration Topology and Decoupling Design for Solar Electric Vehicle

Integration of electric vehicle power conversion units presents a promising solution, yet introduces challenges, including interport power coupling and compromised efficiency in integrated systems. This article proposes a photovoltaic compatible integrated converter combining on-board charger (OBC) with an auxiliary power module (APM), featuring cost effectiveness and high power density. Introduction of a decoupling capacitor enables charging decoupling between high voltage battery (HVB) and low voltage battery (LVB), thereby simplifying multi-port energy management. Furthermore, a minimum current ratio is employed to determine optimal phase shift, achieving minimized conduction losses during HVB charging while maintaining zero voltage switching (ZVS) for all switches. A comprehensive analysis of the proposed converter is conducted, covering operational principles, steady-state performance, soft switching characteristics, efficiency, and loss breakdown, along with control methodology. An experimental prototype rated at 500 W for OBC and 300 W for APM is implemented to validate converter performance. Experimental results demonstrate peak system efficiency of 95.3% during simultaneous HVB and LVB charging, and 93.16% during LVB charging alone, confirming the effectiveness of the proposed converter.