An improved bridgeless interleaved boost PFC rectifier with optimized magnetic utilization and reduced sensing noise

Abstract

An improved bridgeless interleaved boost PFC rectifier is proposed to improve power efficiency and component utilization in this paper. By combining the conventional bridge-less PFC circuit and the interleaved technology, the proposed rectifier is comprised of two interleaved boost branches without the front-end diode bridge. Auxiliary diodes are employed to eliminate undesired circulating loop. The magnetic component utilization is improved by symmetrically coupling two inductors on unique core. According to the interleaved approach, each switch can operate in the whole-line cycle. Moreover, this circuit not only decreases the current stress of the switching devices but also reduces the current and voltage ripple. As operating in critical-conduction-mode (CrM), all the switches can achieve soft-switching characteristics to reduce the switching loss and evidently raise the conversion efficiency. Using a conventional interleaved controller, simple control scheme can be employed to the proposed converter. The operational principle and theoretical analysis of the proposed converter are presented. Finally, an 600 W experimental prototype was built to verify the theoretical analysis and feasibility of the proposed converter. The system efficiency was achieved up to 97.3% with very low current THD.