HIGH POWER FACTOR BUCK-TYPE BRIDGELESS TOPOLOGY FAMILY WITH HYBRID CONVERTER CELLS

Abstract

AC–DC buck-type power factor correction (PFC) converters, with their step-down output voltage capabilities, can serve as promising prestage solutions, enabling end users to operate under relatively low voltage conditions. However, most stat-of-the-art buck-type PFC converters do not set outputs to 160 V or higher due to the concerns about poor power factor (PF) caused by input current dead zones (DZs). This restricted output voltage set limits the buck-type PFC converter applications. Thus, this article proposes a family of hybrid cell-based buck-type bridgeless topologies, derived by combining buck cell with flyback, boost, and buck–boost cells. This combination narrows the input current DZs, enabling a higher output voltage and thus broadening the applications. The proposed topology family with 20 derived topologies is reviewed and analyzed for a comprehensive investigation. Then, a specific topology with high PF and relatively high efficiency is studied. The input PF, output ripple, inductor boundary, control method, and power loss analysis are presented. Experimental tests of the studied topology and performance comparisons with the prior-art bridgeless buck and bridgeless buck–boost PFC converters are conducted to verify the topology feasibility and distinguishing performances.

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