Soft switching active-clamped dual-series resonant converter

Abstract

A soft switching active-clamp dual-series resonant converter is proposed here. Two small transformers are used in the proposed topology to provide more load power. An active-clamp circuit is used to absorb the energy stored in the leakage inductor of transformer, to clamp voltage stresses across switches and to realise the zero-voltage switching turn-on of switches in order to alleviate the switching losses. In order to remove the reverse-recovery problem on output diodes, the zero-current switching turn-off is realised by choosing the proper angle frequency on the secondary side. Analysis of mode operation, design considerations and experimental results of the proposed zero-voltage zero-current switching (ZVZCS) converter are described in detail. Finally, a 200 W ZVZCS prototype treated under Vin=48 V, Vo=200 V is implemented to verify the practicability of the proposed converter.