New ZVS Phase Shift Modulated Full-Bridge Converter Topologies With Adaptive Energy Storage for SOFC Application

This paper presents a new family of zero-voltage switching phase-shift-modulated dc-dc converters for a solid oxide fuel cell application. The proposed converters use a new technique of adaptive energy storage to minimize auxiliary circulating currents for all line and load conditions, thereby maximizing efficiency. A thorough analysis of the proposed topology, including the effects of rectifier junction capacitance, is conducted; and a design procedure presented. Experimental results from a 300 W per bridge, 20 V/300 V prototype are presented to validate the analysis. When compared to a widely used reference topology, the proposed topologies exhibit an efficiency improvement of 7% at full-load.