Charging Pad as the Transformer: Integration of On-board Charger, Auxiliary Power Module and Wireless Charger for Electric Vehicles

Integrated chargers have gained an increasing interest in the electric vehicle (EV) industry. Existing solutions such as the integrated onboard charger (OBC) and auxiliary power module (APM) save the cost and the size, however, it only provides limited functions and hard to be integrated with the future wireless power transfer (WPT) technology. This paper proposed a multi-function magnetic coupler-based integrated charger that provides bidirectional OBC, WPT charging, and APM functions in a single system. In addition to the multi-port converter topology, a multi-winding WPT charging pad is repurposed serving as the main transformer in the OBC and APM modes as well. The paper briefs the system topology, explains various charging modes, and details the magnetic coupler design. Furthermore, a prototype was constructed and successfully delivered 6.6kW in OBC mode, 3.3kW in V2L mode, 6.6kW in WPT mode, and 800W in APM mode, which validates the proposed design.