Design of Push-Pull DC/DC Series-Loaded Resonant Converter Using Linear Transformer

Abstract

In this paper, a push-pull series resonant converter circuit has been developed on MATLAB R2013b software. A push-pull converter is basically derived from step-down converter. A 48V dc voltage source through linear transformer has been converted into dc voltage nearly closer to 5V through diodes. The isolation is provided to the design circuit via the help of linear transformer which is stepping down 440V to 220V ac. The switching frequency of converter is kept 20 kHz and 31.25 kHz so as to avoid transistor hard switching process. For transistor soft switching capacitors (of the order of micro-Farad) have been provided in parallel with the MOSFETs. Also a comparative THD study is done. Further, FFT analysis of output current waveform is done. An attempt has been made to have an output voltage level of the value near 5V.