断续模式下的半无桥Boost PFC变换器设计

Design on Semi-Bridgeless Boost PFC Converter in Discontinuous Conduction

半无桥Boost功率因数校正(PFC)变换器凭借其桥臂无直通风险的优势,广泛应用于军工、医疗等高可靠性应用场合。电流断续模式(DCM)下,Boost PFC变换器具有零电流开通、二极管无反向恢复等优点。针对传统控制方式下输入电压过高导致的电流畸变和功率因数降低等问题,首先在恒定占空比控制的基础上详细推导了变占空比的控制方式,从而在全范围内提高功率因数。其次,为解决传统的半无桥Boost PFC变换器使用2个功率电感带来的系统体积、占板面积大等问题,采用完全解耦的磁集成方式来提高功率密度。最后,搭建了1台150 W基于完全解耦磁集成的半无桥Boost PFC变换器,实验验证了所提方案的有效性。

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.