Soft-Switching Bidirectional Isolated Full-Bridge Converter With Active and Passive Snubbers

A bidirectional isolated full-bridge dc-dc converter with a conversion ratio around nine times, soft start-up, and soft-switching features for battery charging/discharging is proposed in this paper. The converter is equipped with an active flyback and two passive capacitor-diode snubbers, which can reduce voltage and current spikes and reduce voltage and current stresses, while it can achieve near zero-voltage-switching and zero-current-switching soft-switching features. In this paper, the operational principle of the proposed converter is first described, and its analysis and design are then presented. A 1.5-kW prototype with a low-side voltage of 48 V and a high-side voltage of 360 V has been implemented, from which measured results have verified the discussed features.