Design of high efficiency phase-shift full-bridge converter with minimized power loss on primary-side clamp diodes

Abstract

Phase-shift full-bridge (PSFB) converter is a full-bridge converter that adopts a phase-shift control scheme to achieve zero-voltage-switching (ZVS). Owing to its low voltage/current stress, it is popular for high efficiency and high power density applications. Practically, to reduce the high peak voltage of secondary rectifiers, its configuration contains clamp diodes on the primary side. However, this circuit configuration causes additional power loss due to the current flowing through the clamp diodes. In this paper, an additional capacitor applied to PSFB converter is proposed to reduce unnecessary power loss, and its validity is proved experimentally by an 800 W power supply.