Soft Switching Interleaved Forward Converter with Current Doubler Rectifier

A soft switching interleaved forward converter with current doubler rectifier is presented in this paper. Active clamp circuit is used in the primary winding of transformer to recycle the energy stored in the leakage inductor and magnetizing inductor so that the voltage stresses of switches are reduced. The leakage inductance of transformers, the magnetizing inductance and the clamp capacitance is resonant to achieve zero-voltage switching (ZVS) of clamp switches. The resonance between the leakage inductance of transformer and output capacitance of switch will achieve ZVS operation for the main switches in the proposed converter. The interleaved operation can reduce the current ripple on the output capacitor. Two current doubler rectifiers with ripple current cancellation are connected in parallel at the output side to reduce the current stress of the secondary winding of transformer. All these features make the proposed converter suitable for the dc-dc converter with high output current. The operation principle and system analysis of the proposed converter are provided in detail. Finally, experimental results, taken from a laboratory prototype rated at 125 W and the switching frequency of 150 kHz, are presented to verify the feasibility of the proposed converter.