Two-switch Pseudo Continuous Conduction Mode Buck-Boost Power Factor Correction Converter

A novel two-switch Buck-Boost power factor correction(PFC) converter operating in pseudo continuous conduction mode(PCCM) and its corresponding control strategy were proposed in this paper.The two-switch PCCM Buck-Boost PFC topology provides an additional degree of control freedom to realize PFC control,which can offer significant performance improvements over single-switch Buck-Boost PFC converters or two-switch Buck-Boost PFC converters in continuous conduction mode(CCM) and discontinuous conduction mode(DCM).The additional degree of control freedom introduced by inductor current freewheeling stage helps to achieve unity power factor control.Besides,inductor current ripple of the two-switch PCCM Buck-Boost PFC converter,which is lower than that of the two-switch DCM Buck-Boost PFC converter,can be obtained.Analysis,simulation and experiment results of the two-switch PCCM Buck-Boost PFC converter were presented.The experiment results show that the dynamic response of the two-switch PCCM Buck-Boost PFC converter is significantly faster than that of the two-switch CCM and DCM Buck-Boost PFC converter.