A New Standby Structure Based on a Forward Converter Integrated With a Phase-Shift Full-Bridge Converter for Server Power Supplies

Abstract

This paper presents a new standby structure where a forward converter is integrated with a dc–dc phase-shift full-bridge (PSFB) converter for server power supplies. While a typical standby structure consists of an independent flyback converter, the proposed standby structure is integrated with one leg of the dc–dc PSFB converter. Its main advantages are that the voltage across a standby switch is clamped at the link voltage across the link capacitor and that the standby switch achieves zero-voltage switching over entire load range. The validity of the proposed standby structure is confirmed by the experimental results from 12 V/58 A for the dc–dc output prototype and 11.5 V/1.5 A for the standby output prototype.