Continuous-conduction-mode SEPIC converter with low reverse-recovery loss for power factor correction

A continuous-conduction-mode SEPIC converter with low reverse-recovery loss is proposed for power factor correction. The proposed SEPIC converter can reduce the reverserecovery loss of the diodes and improve the power efficiency. By utilising a coupled inductor and an additional diode, zero-current turn-off of the output diode is achieved. The reverse-recovery current of the additional diode is reduced by the leakage inductor of the coupled inductor. The proposed SEPIC converter provides high power efficiency and high power factor compared to the conventional PFC circuits employing the SEPIC converter. An operation principle and a detailed analysis of the proposed converter are presented. Experimental results are discussed for a 300W (330 V/0.9 A) prototype under the universal input voltage (90–265 V). It is shown that the efficiency of the SEPIC converter can be significantly improved.