Efficiency Enhancement of Bridgeless Buck-Boost PFC Converter with Unity PF and DC Split to Reduce Voltage Stresses

This paper proposes a unity power factor (PF) bridgeless buck-boost power factor correction (PFC) converter to minimize conduction losses caused by the diode bridge. Moreover, compared to the conventional buck-boost PFC converter, the proposed converter has lower voltage stresses across switches, which further improves the overall efficiency of the proposed converter, especially when it operates in the light load conditions. Operation modes with inductors working in the discontinuous conduction mode (DCM) are given in detail, and comparative analysis is conducted to show the proposed converter performance regarding the PF, component stresses, and output ripple. The proposed and conventional converter prototypes with load range of 20∼100 W are built and tested. The obtained results verify merits and theoretical predictions of the proposed.