Analysis and Design of a Battery Charger with Interleaved PFC Based on an Asymmetrical Half-Bridge Topology

In this paper, analysis and design of a zero voltage switching (ZVS) isolated single-stage charger with interleaved power factor correction (PFC) based on an asymmetrical half-bridge topology is presented. The proposed charger is formed from an interleaved PFC converter and an asymmetrical half-bridge converter. It has the features of constant frequency operation, ZVS and low voltage stress imposed on the active switches. Moreover, it can achieve high power factor, high power density, high efficiency, low switching loss and low component count, which make converter operation at medium power levels feasible. In the paper, theoretical analysis and experimental results of a charger with the proposed topology have verified that power factor (PF) and total harmonics distortion (THD) can be significantly improved. In addition, input current ripple can be also reduced which in turn can reduce the size of line filter. The proposed charger is attractive for electric vehicle (EV) applications.