A current-fed three-phase half-bridge dc-dc converter with active clamping

This paper describes a new current-fed three-phase half-bridge DC-DC converter with active clamping for fuel cell applications. The proposed DC-DC converter has a three-phase interleave step-up converter structure consisting of three input inductors, three active switches at the primary and a diode rectifier at the secondary. The input ripple current is minimized by three phases interleave operation, and the transformer turn ratio is reduced by its inherent boost mode operation effectively. The active clamping circuit with simple operation principle at the primary enables not only to absorb the voltage surge across the power switch at turn off but also to achieve ZVS of all active switches of the converter. The various experimental results are presented to verify the feasibility of the proposed DC-DC converter.