A single-stage power-factor-corrected AC/DC converter

摘要

This paper presents a single-stage isolated converter topologyndesigned to achieve a regulated DC output voltage having nonlow-frequency components and a high-input power factor. The topology isnderived from the basic two-switch forward converter, but incorporates annadditional transformer winding, inductor and a few diodes. The proposedncircuit inherently forces the input current to be discontinuous and ACnmodulated to achieve high-input power factor. The converter output isnoperated in discontinuous mode to minimize the bulk capacitor voltagenvariations when the output load is varied. Analysis of the converter isnpresented, and performance characteristics are given. Design guidelinesnto select critical components of the circuit are presented. Experimentalnresults on a 150 W 50 kHz universal input (90-265 V) 54.75 V outputnAC/DC converter are given which confirm the predicted performance of thenproposed topology