Analysis and design of a new high-efficiency bi-directional ZVT PWM converter for dc bus and battery bank interface

This paper proposes a new high-efficiency bidirectional ZVT (zero-voltage transition) PWM (pulse width modulation) power converter for a DC bus and battery bank interface. The proposed converter can operate as battery charger when the utility is within its acceptable voltage range and supply energy to critical loads when the utility fails. This converter practically eliminates both the low and high frequency current ripple in the batteries, thus maximizing battery life without penalizing the volume of the converter. Moreover, soft-switching of all switches is achieved using the proposed auxiliary commutation circuit. This auxiliary circuit has few components and low reactive energy, increasing the efficiency of the converter. Experimental results based on a 580 W prototype are presented to validate the analysis and the proposed design procedure as well as to demonstrate the performance of the proposed approach