Hybrid PWM-Resonant Converter for Electric Vehicle On-Board Battery Chargers

A novel hybrid pulse-width-modulation resonant converter is presented in this paper for electric vehicle (EV) 3.3-kW on-board battery chargers (OBCs). While the proposed converter has all the benefits of the earlier developed hybrid converters for OBCs, the proposed converter has fewer components and achieves much lower voltage stress in the rectifying diodes compared to the earlier hybrid converters. As a result, it is possible to employ superior diodes such as Schottky barrier diodes below 300 V featuring low forward-voltage drop and better reverse-recovery for EV 3.3-kW OBC applications. In addition, the proposed converter achieves much better transformer utilization compared to the earlier hybrid converters. Due to this, the proposed converter can achieve more optimal efficiency over the overall battery charging profile. The effectiveness of the proposed converter has been verified with the experimental results under an output voltage range of 250-420-V dc at 3.3 kW.