Bridgeless Step-Down PFC Converter Based on Dual-Resonant Switched-Capacitor Structure with Continuous Conversion Ratio

Power factor correction (PFC) converter is widely utilized in grid-connected equipment and power adapter, etc. Conventional PFC Buck converter is not proper to maintain good performance at low output voltage with a wide input range. In the bridge-based PFC converter, the forward voltage of rectifier diodes is an important source of power loss. For overcoming the above-mentioned issues, a bridgeless PFC converter based on switched-capacitor dual-resonance tank is proposed in this paper. The switched-capacitor dual-resonance tank is meaningful to improve voltage regulating capacity and the bridgeless structure is helpful to eliminate rectifier diode loss. Additionally, only small inductors are utilized in the proposed PFC converter, which is useful to improve power density.