High Efficiency Asymmetric Dual Active Clamp Forward Converter with Phase-Shift Control for Small Conduction Loss

In this paper, an asymmetric dual active clamp forward (ADACF) converter for reducing the sizeable primary conduction loss is proposed. By changing the position of one of two ACF cells and by adding the secondary winding of one transformer, the high DC voltage gain can be achieved. Furthermore, the phase-shift control adjusts the overlapping duty with the main switches turned on at the same time so that the voltage gain can also be increased. Due to the high voltage gain for the above reasons, the large turns ratio of transformers can be designed, and the proposed converter can improve high efficiency by reducing the large primary conduction loss without additional semiconductor devices and complex circuits. To verify the proposed converter, 36-72 V
DC
input voltage and 480 W (12 V
DC
/40 A) output prototype has been implemented.