Performance analysis of bridgeless DCM SEPIC rectifier for universal input voltage applications with fast dynamic response

This paper analyzes the operation of a bridgeless SEPIC rectifier for universal input voltage applications. Compared to conventional full bridge topology, the proposed SEPIC rectifier provides lower conduction losses and heating due to absence of input bridge rectifier and presence of single switching device in each half cycle. The topology is designed in discontinuous conduction mode (DCM) to achieve almost unity power factor and low THD of input current. The DCM operation provides zero current turn on for power switches and simple control circuitry. The small signal modelling is done for universal line voltage range. Further, the comparative study for open loop and close loop is analyzed.