Modified Isolated Bridgeless SEPIC PFC Converter for EV Battery Applications

EVs are becoming popular as they reduce carbon footprint. However, battery charging remains the biggest challenge in the EV transportation system. PFC and dc-dc converters are the two critical stages in the charging process. Various power electronics converter configurations such as cuk, Zeta, SEPIC, and buck-boost converter are employed to charge EVs. PFC circuits used in EV battery chargers are inefficient due to conduction losses from the diode bridge rectifier (DBR). This research proposes a solution by presenting a bridgeless single-ended primary inductance converter that resolves this inefficiency problem. The converter uses an input current with a unity power factor during each switching cycle and transforms it into a sinusoidal waveform to enhance power quality, ensuring compliance with IEC-61000-3-2 PQ standards. The proposed 5.7kW, 65V converter is evaluated through analysis using PSIM in dynamic and steady-state scenarios, charging a 48V 500Ah electric vehicle battery. The charger’s performance is improved by utilizing constant current (CC) for SoC < 80% and constant voltage (CV) charging methods for SoC > 80%.