An Isolated/Bidirectional PWM Resonant Converter for V2G(H) EV On-Board Charger

This paper suggests another candidate for isolated/bidirectional dc/dc converter in electric vehicle on-board charger based on PWM resonant converter (RC). The PWM-RC has good switching characteristics but it is not adequate for bidirectional applications because it is always operated under “buck type” operation regardless of power flow directions. This problem can be solved by structure change method, which increases the converter gain into double. Also, additional technique to increase the converter gain during discharging operation is suggested by analysis of the gain characteristics. The feasibility of bidirectional PWM-RC is verified with a 6.6-kW prototype charger.