A boost PFC rectifier with a passive lossless snubber circuit using coupled inductors methods

In this paper, a boost PFC rectifier with a novel passive lossless snubber circuit is proposed to minimize switching loss for high power applications. The proposed lossless snubber is composed of the coupled inductors merged to the boost inductor. The proposed lossless snubber compared with the conventional methods doesn't need additional inductor cores and reduces the extra cost for the soft switching operation. A new turn-on mechanism of the lossless snubber using coupled inductor is applied to reduce the reverse recovery loss of the output diode rectifier. During the turn-off operation, the lossless snubber is composed of a single capacitor and two diodes to reduce the voltage stress and the turn-off power loss. Due to the lossless clamping operation, the proposed PFC operates under soft switching conditions with high power conversion efficiency. The design and performance of the boost PFC rectifier using the proposed lossless snubber are verified by experimental results using a 3.3kW prototype rectifier.