Analysis and design of a Single Stage Single Switch Power Factor converter to reduce bus voltage stress with high input power factor and fast output voltage regulation

Single Stage Single Switch Power Factor converter is an integration of input power factor current shaper and a DC to DC output stage utilizing single control switch and having isolation between input and output providing wide band width response. The focus of the topology is to reduce the DC bus voltage at light load without compromising with input power factor. This paper presents detailed analysis and optimal design of DCM (Discontinuous Conduction Mode) boost rectifier - CCM (Continuous Conduction Mode) fly back SMR by introducing Equal Area Criterion (EAC) in the design of boost inductance. And a simple low cost analog controller is proposed for unity power factor, low dc bus voltage stress and fast regulation. Design, simulated studies using Orcad and experimental verifications have been performed for a 100W, 230V AC - 50V DC SMR. DC bus voltage stress during light load condition is observed. Under closed loop condition the stress was found almost eliminated.