Steady state analysis for an off-line series resonant converter

Abstract

A steady state analysis of an offline, high frequency series resonant converter that operates from 200 VDC and produces 5.0 VDC at 10 A is presented. Regulation is accomplished through varying the switching frequency while keeping the ON time of the switch constant. The switching cycle is split into separate stages, each stage analyzed through a description of its state equations. Some of the features of this converter are: the switches turn both on and off into zero current, the inductor (L) current and capacitor (C) voltage waveforms have finite slopes causing less electromagnetic interference (as opposed to pulse-width-modulation converters) the transformer's leakage inductance can be used in part or entirely as the resonant inductor, and the current in L and the voltage across C do not resonate continuously-instead, they assume fixed values at the end of every cycle.<>