A Comparative Study on PFC Bridgeless Flyback and SEPIC AC-DC Rectifiers Operating in DCM and BCM

This paper presents a comparative study on the power factor corrector bridgeless SEPIC and Flyback ac-dc rectifier. First, a new SEPIC-based topology is proposed based on the existing Flyback topologies to remove the need of the input filter due to the existence of the input inductor in the SEPIC circuit. Then, both converters are analyzed and compared when operating in DCM and BCM, to evaluate the benefits of operating in BCM such as lower current stress on the switches and output diodes and hence lower conductive losses.