High Gain Soft-Switching Bidirectional DC–DC Converter for Eco-Friendly Vehicles

This paper proposes a nonisolated soft-switching bidirectional dc-dc converter suitable for high step-up and step-down applications. The proposed converter can achieve zero voltage switching turn on of all switches and zero-current-switching turn off of some switches in continuous conduction mode in both forward and reverse modes. An optimized switching strategy is presented to minimize switch current rating and achieve soft switching in wider range. An intermediate switching pattern is introduced to carry out seamless mode change. Experimental results from a 5-kW prototype are provided to validate the proposed concept.