Single-phase two-switch PCCM buck-boost PFC converter with fast dynamic response for universal input voltage

A novel single-phase two-switch pseudo-continuous conduction mode (PCCM) buck-boost PFC converter and its corresponding control strategy are proposed in this paper. The two-switch PCCM buck-boost topology provides an additional degree of control freedom to realize PFC control, which can offer significant performance improvements over single-switch buck-boost converters or two-switch buck-boost converters in continuous conduction mode (CCM) and discontinuous conduction mode (DCM). A simple and fast voltage control loop can be designed to realize output voltage regulation. The additional degree of control freedom introduced by inductor current freewheeling operation helps to achieve unity power factor control. Analysis and simulation results of PCCM buck-boost PFC converter have been presented. The experiment results show that the dynamic response of the PCCM buck-boost PFC converter is significantly faster than the CCM and DCM buck-boost PFC converter.