A novel soft-switching bridgeless power factor correction circuit

Abstract

A novel zero- voltage- transition (ZVT) bridgeless power factor correction circuit (PFC) was proposed. An auxiliary circuit, consisting of a resonant inductor, two blocking diodes, one wheeling diode and an assist MOSFET, was used to reduce the turn-on switching loss of the two main switches of the bridgeless PFC circuit. Soft commutation of the main switches is achieved without imposing additional voltage stress on the main switches. Feedback gate-drive signals were obtained by using existing converter IC controller. In this paper, a detailed description of the operation of the proposed circuit will be given. Based on the analysis, guidelines for the component selection are presented. A prototype of 100-kHz, 600-W, universal-line PFC bridgeless circuit was built to verify the proposed scheme.