A 6.6kW high power density bi-directional EV on-board charger based on SiC MOSFETs

This paper presents a SiC MOSFET-based 6.6 kW bi-directional Electric Vehicle (EV) on-board charger (OBC), with high efficiency and high power density. A digital controlled prototype with a switching frequency of 67kHz for CCM totem pole PFC, and 150kHz-300kHz for a CLLC resonant converter is demonstrated with 54W/in3 power density exceeding 96.5% in peak efficiency. In order to achieve a high power density, all SiC MOSFETs are mounted on a tooled AL heat sink, with all magnetics potted internally. MOSFETs and magnetics meet thermal requirements on a 65°C cooling plate.