Voltage oscillation reduction technique for phase-shift full-bridge converter

Abstract

A conventional phase-shift full-bridge converter (PSFB) has a serious voltage oscillation problem across the secondary rectifier diodes. To overcome this problem, a new voltage oscillation reduction technique (VORT), which effectively reduces the rectifier voltage oscillation by a simple manner, is proposed. The concept of the VORT is utilizing the operation of the leading leg transition, which does not cause a severe voltage oscillation across the rectifier, to the lagging leg transition, and it is implemented simply by employing only a resonant capacitor in series with the transformer secondary and a small magnetizing inductance of the transformer without any lossy components. Moreover, the VORT can realize ZVS for all switches along a wide load range. The concept, operational principle and oscillation analysis of the VORT are presented and verified experimentally.