COMPREHENSIVE STUDY OF HIGH FREQUENCY TRANSFORMER DESIGNING FOR MODIFIED FLYBACK CONVERTER

Abstract

Thepaperpresents a special function improvedFlyback converter isoperate with better efficiency and compactsize, which isprevail overmost of the basicflyback converter downsides, and also keeping its inexpensiveness and lucidity. In certain, the converter permitsthe MOSFET OFF voltage to be less in amountand clamped to the input, thus healing the transformer leakage energy. As a result of effect, the duty cycle can be increaseto unity, thus reducing the voltage stress across the output rectifier, and minimizingboth the magnetizing inductance and the transformer bias current values. Moreover,to the auxiliary mosfet, the magnetizing current willnegative, abolishthe discontinuous conduction mode (DCM) of the basic Flyback and permits a smaller magnetizing inductance is to be selected. Besides, in contrastwith the basicFlyback, the energy is supplied to the secondary side not only from the magnetizing inductance, but also from the introduced series capacitor, minimizingthe transformer energy necessity. The improvedconverter makes also the soft-transitions possible for both mosfet. For all these reasons, as a moreeffective and compactsize approximate, this topology shows better fulfillments in high power density inexpensive applications.