A Bridgeless Single-Stage Half-Bridge AC/DC Converter

This paper proposes a new bridgeless single-stage half-bridge ac-dc converter for power factor correction. The proposed converter integrates the bridgeless boost rectifier with the asymmetrical pulse-width modulation half-bridge dc-dc converter. The proposed converter provides an isolated dc output voltage without using any full-bridge diode rectifier. Conduction losses are lowered by eliminating the full-bridge diode rectifier. Zero-voltage switching of the power switches reduces the switching power losses. The proposed converter gives a high efficiency, high power factor, and low cost. The effectiveness of the proposed converter is verified on a 250 W (48 V/5.2 A) experimental prototype. The proposed converter achieves a high efficiency of 93.0% and an almost unity power factor for 250 W output power at 90 V-rms line voltage.