A Reconfigurable Totem-Pole PFC Rectifier With Light Load Optimization Control Strategy and Soft-Switching Capability

Abstract

This article presents a reconfigurable totem-pole bridgeless power factor correction converter employing an auxiliary circuit and a simple control scheme to achieve high efficiency. Under light load condition, instead of delivering the energy through the main switch, the proposed converter utilizes only the auxiliary switches by using a different control scheme. Since the auxiliary switches have much smaller parasitic capacitances than the main switches, the proposed converter can obtain high efficiency under light load condition. Over middle-to-heavy load condition, the proposed converter can acquire both zero-voltage switching operation and relieved reverse-recovery problem thanks to the auxiliary circuit, which leads to high efficiency even with Si-MOSFET in the continuous conduction mode control. As a result, the proposed converter can achieve high efficiency over the entire load condition. The effectiveness of the proposed converter is verified by a prototype with ac 230V(rms) input and 750 W output.