Abstract:

The semi-bridgeless Boost power factor correction (PFC) converter is favored for its low risk of direct conduction in the bridge arm,making it ideal for high-reliability applications like military and medical fields.Operating in discontinuous conduction mode (DCM),this converter offers advantages such as zero-current turn-off and diode reverse recovery elimination.Addressing the issue of current distortion and reduced power factor caused by excessive input voltage under traditional control methods, a variable duty cycle control strategy based on constant duty cycle control is elaborated,enhancing the power factor across the entire input range.Additionally,to solve the challenges associated with traditional semi-bridgeless Boost PFC converters,such as large system volume and board footprint due to dual power inductors,an integrated magnetic coupling approach is adopted to enhance power density.Finally,a 150 W semi-bridgeless Boost PFC converter based on fully integrated magnetic coupling is constructed and experimentally validated for its efficacy.

Key words: semi-bridgeless Boost PFC, discontinuous conduction mode, variable duty cycle control, magnetic integration