ZVS DC-DC Converter with Parallel-Connected Current Doubler Rectifier

A soft switching converter with parallel-connected full-wave rectifiers is presented. In the proposed converter, the primary windings of two transformers are connected in series. Two full-wave rectifiers with ripple current cancellation are connected in parallel at the output side to reduce the current stress of the secondary winding of transformer. The clamp circuit based on an auxiliary switch and a clamp capacitor is connected in parallel with the primary side of the transformer to recycle the energy stored in the leakage inductance. The leakage inductance of transformers, the magnetizing inductance and the clamp capacitance is resonant to achieve zero-voltage switching (ZVS) of auxiliary switch. The resonance between the leakage inductance of transformer and output capacitance of switch will achieve ZVS operation for the main switch in the proposed converter. The pulse-width modulation technique is adopted to regulate the output voltage. Experimental results for a 200 W (5 V/40 A) prototype are given to demonstrate the effectiveness of the proposed converter