High efficiency current-doubler rectifier with low output current ripple and high step-down voltage ratio

This paper presents a current-doubler rectifier with low output current ripple and high step-down voltage ratio. In the proposed rectifier, two extra inductors are introduced to extend the duty ratio of switches which in turn can reduce the peak current through the isolation transformer and lower output current ripple, and two extra diodes are used to provide discharge paths for the two extra inductors. To highlight the merits of the proposed rectifier, its performance indexes, such as voltage gain function, secondary winding peak current of the isolation transformer and output current ripple, are analyzed and compared with the conventional current-doubler rectifier. In this study, a ZVS phase-shift full-bridge converter with the proposed rectifier, input voltage of 400 V, output voltage of 12 V, and full load power of 500 W has been implemented and verified, from which experimental results have shown that 90 % conversion efficiency can be achieved at the full load.