Design and Optimization of a Current-Driven Phase-Shift Full-Bridge Converter with GaN Devices and Large Conversion Ratio

High-efficiency, high power density and large conversion ratio are the most considerable characteristic in the Power Processing Unit (PPU) for spacecraft electric propulsion (SEP) applications. The current-driven phase-shift full-bridge (CD-PSFB) converters have been drawing many attentions due to their wide ZVS range and no voltage spikes across the output diode. Therefore, they would be good candidates for SEP applications. This paper presents a high voltage gain CD-PSFB converter with newly emerged gallium nitride (GaN) devices to further increase the power density and efficiency. The operation principles and DC voltage gain are presented. The ZVS conditions are also analyzed and finally a 300-kHz 200-W 28-250V high output voltage CD-PSFB converter are designed and made to validate feasibility of the proposed converter.