Electromagnetic interference frequencies prediction model of flyback converter for snubber design

Abstract

Snubber design for flyback converters usually requires experimental prototype measurements or simulation based on accurate and complex models. In this study simplified circuit modelling of a flyback converter has been described to dimension snubbers in early stage of design process. Simulation based prediction of the transistor and diode ringing frequencies has been validated by measurements in a prototype setup. In that way obtained simulation data enabled fast and precise snubbers dimensioning. Application example has illustrated effectiveness of the proposed methodology by line impedance stabilisation network (LISN) spectra evaluation of the experimental flyback converter resulting from snubbers dimensioning.