Bridgeless Discontinuous Conduction Mode SEPIC Power Factor Correction rectifier

This paper deals with the simulation and hardware implement of Single phase AC-DC Bridgeless Discontinuous Conduction Mode (DCM) with Single Ended Primary Inductance Converter (SEPIC) for Power Factor Correction (PFC) rectifier. The topology is improved by the absence of an input diode bridge and the presence of only two semiconductor switches in the current flowing path during each switching cycle which results in lesser conduction losses and improved thermal management compared to the conventional SEPIC converters. By implementing the improved topology in DCM it ensures almost unity power factor in a simple and effective manner. The DCM operation gives additional advantages such as zero-current turn-on in the power switches, zero-current turn-off in the output diode and reduces the complexity of the control circuitry. Performance comparisons between the improved and conventional SEPIC PFC rectifier are carried out using Pspice software and results are presented.