Analysis of ZVS/ZCS soft-switching dual-resonant converter

A soft-switching converter with dual resonant structures is presented in this paper. The dual resonant tanks are composed by the leakage inductors and resonant capacitors to achieve zero-current-switching (ZCS) turn-off mechanism for diodes at the secondary side of transformer. Moreover, the voltage stresses of power switches are clamped by the active clamp circuit at the primary side of transformer. The active clamp circuit is not only absorbed the energy stored in the leakage inductor but also create zero-voltage-switching (ZVS) turn-on feature for power switches. Hence, the reverse-recovery problem can be eliminated. The operational principles, design consideration and realization are discussed. Finally, experimental results from a 400 W prototype are presented to confirm the effectiveness of the proposed converter.