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

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.