Hybrid Converter Cell-Based Buck-Type Bridgeless PFC Converters With Low THD

Abstract

AC-DC buck power factor correction (PFC) converters with relatively high efficiency are good candidates in low-voltage applications. However, they typically suffer from high input current total harmonics distortions (THDi) caused by the input current dead zones. Thus, this paper proposes four hybrid cell-based buck-type bridgeless PFC converters by using the buck and buck-boost or flyback converter cells. Thanks to the buck-boost/flyback operation in one half-line cycle, the dead zones can be minimized and thus the reduced THDi. The operation modes of one proposed bridgeless topology are introduced, followed by a theoretical analysis. Validations of the proposed converters are conducted in simulations, along with the comparison with other buck-type PFC converters.