A 5kW Bidirectional Isolated On-Board EV Battery Charger Using Hybrid PFC/Inverter

This paper presents a bidirectional on-board charger used in Electrical Vehicles. This charger includes a front-end hybrid PFC/inverter using SEPIC/Zeta converter followed by an isolated symmetric full-bridge CLLC converter. SEPIC PFC maintains DC link voltage in charging mode using feedback from battery pack voltage. Consequently, by switching the CLLC converter near the resonant frequency, an appropriate voltage will charge the battery. The Zeta converter supplies the inverter at the specified voltage value regardless of DC link voltage in discharging mode. Moreover, zero voltage turn on switching at the primary side and zero current turn off switching at the secondary side are considered in the design of the CLLC to improve the power conversion efficiency. MATLAB/Simulink is used to validate the performance of the proposed charger. Simulations are carried out from 20% of the rated power to full load. Simulations results indicate that the power factor and the THD of the input current in charging mode and the THD of the output voltage in discharging mode agree with standards.