Sinusoidal Phase Shift Modulation for V2H Operational Mode in Current-Fed Bidirectional Onboard Charger

This article proposes a sinusoidal phase shift modulation for a single-stage (1-S) L-L type, electrolytic capacitorless, current-fed bidirectional converter during vehicle-to-home (V2H) operation. On the ac side, there is a current-fed half-bridge converter (CFHB), and on the dc side, there is a voltage-fed full-bridge converter (VFFB). The ac and dc side converters are isolated by a high-frequency transformer (HFT). DC-side bulky electrolytic capacitors have been replaced with small film capacitors to filter out switching frequency current ripple and allow sinusoidal ripple current (SRC) charging. A simple control architecture regulates the output ac voltage for residential loads in V2H operational mode. The proposed modulation, along with a seamless transition to V2H operational mode in the event of a grid outage, is experimentally validated in a developed 1.5 kW laboratory prototype. Furthermore, with the proposed modulation technique, the presented 1-S onboard charger (OBC) can achieve zero voltage switching (ZVS) and zero current switching (ZCS) under wide ac and battery voltage ranges resulting in high efficiency across loading conditions.