A PFC based EV battery charger using a bridgeless SEPIC converter

摘要

Conventional PFC circuits in EV (Electric Vehicle) battery chargers have the efficiency limitation due to high conduction loss associated with a diode bridge rectifier (DBR) at the input. To mitigate this issue, a bridgeless single ended primary inductance converter (SEPIC) with improved power quality is presented in this paper. The input current drawn by the charger shows a unity power factor operation in a complete switching cycle. Due to elimination of DBR, conduction losses are significantly reduced. The proposed converter works well for making the input current perfectly sinusoidal along with an improved power quality parameters which conforms to the limits prescribed by international IEC-61000-3-2 PQ standard. The overall performance of the proposed 1kW, 65Vconverter is described with the help of various operating modes, design equations and MATLAB based analysis in steady state as well as dynamic conditions for charging a 48V 100Ah battery for EV. The battery is charged at constant current/ constant voltage control mode and it provides satisfactory results for inherent power factor correction, thus, improving overall performance of the charger.