Isolated flyback-current-fed push-pull converter for power factor correction

This paper presents a single-stage high-power factor isolated power supply based on the classical flyback-current-fed push-pull converter. The proposed converter operates as a buck one at a duty-cycle below 50% and as a boost one at duty-cycle above this range. Therefore, when properly driven, this converter is suitable for high power factor applications, with many advantages when compared with the boost-isolated current-fed converter, including inrush current control and less voltage stress over the power semiconductors. Theoretical analysis, design methodology, design example, control strategy, and experimental results are presented is paper