Design optimization of an off-line input harmonic current corrected flyback converter

Abstract

Characterization of bulk capacitor voltage stress in a single-switch, input harmonic current corrected flyback converter is presented. A design procedure for optimizing such a converter design by limiting the bulk capacitor voltage stress, maintaining high efficiency while complying with IEC 1000-3-2 class D input harmonic current requirements is introduced. A 60 W universal input, 5 V at 12 A power supply designed following the procedure was built, and the theoretical prediction of bulk capacitor voltage as well as the predicted input harmonic contents are verified experimentally.