A novel interleaved flyback-typed converter with ZVS operation

Abstract

This paper presents a novel interleaved dc-to-dc converter that is mainly composed of two flyback converters. Prior to turning on the active switch of one flyback converter, its parasitic capacitance is discharged to nearly zero voltage by the induced current in the secondary winding of the coupled inductor of the other flyback one. By this mean, both active switches can achieve zero-voltage switching on (ZVS) without needing to use any active-clamping circuit or snubber circuit. In spite of improving the overall circuit efficiency, ZVS operation can eliminate the current spike in the active switch, leading to increase the circuit reliability. The steady-state analyses at different operation modes and the mathematical equations are provided. Finally, a 200-W prototype circuit was built and tested to verify the analytical predictions. Satisfactory performances are obtained from the experimental results.