A Zero-Voltage-Switching Four-Switch Buck-Boost PFC Converter

In this paper, a zero-voltage-switching (ZVS) four-switch buck-boost (FSBB) power factor correction (PFC) converter is proposed, which not only achieves flexible output voltage, but also realizes ZVS for the power switches with fixed switching frequency. The operating principle of the FSBB PFC converter is analyzed, and the ZVS condition for the power switches is derived. Based on that, the design of the inductor is proposed and the output voltage is optimized for improving the efficiency. Then, the control scheme for the FSBB PFC converter is given. Finally, a prototype of 500-W FSBB PFC converter is fabricated and tested in the lab, and the experimental results are provided to verify the effectiveness of the design and control scheme.