Analysis and Implementation of a Dual Resonant Converter

A dual resonant converter with two transformers is presented in this paper. Dual resonant tanks are composed of leakage inductors and resonant capacitors to achieve zero-current-switching turnoff for rectifier diodes at the secondary side of the transformer. Hence, the reverse-recovery problem of the rectifier diodes can be eliminated. Moreover, the active-clamp circuit does not only absorb the energy stored in the leakage inductor but also clamp the voltage stress of power switches. Compared to the conventional dual resonant converter, the zero-voltage switching operation of the proposed converter is easily achieved by using two transformers. The operation principles, design considerations, and realization are discussed in detail. Finally, experimental results from a 400-W laboratory prototype are presented to confirm the effectiveness of the proposed converter.