High power factor single-stage ZVS charger with coupled inductors

This paper presents a zero voltage switching (ZVS) single-stage charger with power factor correction (PFC) based on an asymmetrical half-bridge topology and coupled inductors. The proposed charger is formed from a PFC converter and an asymmetrical half-bridge converter. Coupled inductors are adopted to reduce input current ripple caused by asymmetrical PWM operation, resulting in small input filters: The converter 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 for a charger with the proposed topology have been obtained, which verify its feasibility.