Abstract:
In this proposed new converter is an inherent integration of a buck converter and a flyback converter, which operates in either fly back mode or buck mode according to whether the input voltage is lower or higher than the output voltage.In this way, the dead zones of ac input current in traditional buck PFC converter are eliminated.Therefore, the proposed integrated buck–fly back non- isolated PFC converter can achieve high PF under universal ac input range.A proposed converter will be simulated in MATLAB/SIMULINK environment.A 100-W prototype was built up to verify the theoretical analysis of the proposed integrated buck–flyback non-isolated PFC converter. Objective of this proposed topology is modeling of High power factor correction converter by integration of a buck–Fly back input current shaper with a Auxiliary fly-back converter.proposed converter operates in fly back mode when the input voltage is lower than the output voltage and operates in buck mode when the input voltage is higher than the output voltage.

Keywords: AC-DC, buck-flyback converter, harmonics currents, high power factor(PF)