A high performance bridgeless AC-DC-DC power factor corrector for LED driver application

For LED lighting system the quality of the power is an important issue. For better utilisation and quality the power factor should be unity. Thus LED system must have a PFC circuit before the signal drives the LED. In this paper a single stage bridgeless Single Ended Primary Inductor Converter (SEPIC) for LED driver application is presented. The main feature of proposed converter is that it has only one switch with bridgeless topology. To facilitate the feedback control it is necessary to obtain a linear model of the system by using which the system stability analysis can be performed. Thus the paper also presents the modeling of the proposed converter using state space averaging technique for stability analysis. In the proposed topology there is presence of un-damped complex poles and zeros which makes the system unstable. So a modified topology is presented with its modeling using suitable damping network. A 60V/180W model is designed to evaluate the performance. Simulation results are presented to validate the model.