New start-up schemes for isolated full-bridge boost converters

Abstract

Two new start-up schemes for isolated full-bridge boost converters are proposed in this paper. The control timing for each scheme, which is compatible with the PWM control timing for the normal boost mode operation, is investigated. Design considerations on the relationships between the turns ratios of the boost choke windings and the main transformer windings, and its effects on the operation of the converter, are studied. The two proposed start-up schemes are experimentally verified on a 1.6 kW, 12 V/288 V prototype.