Isolated DC/DC Converter for RF generator of a Power Propulsion Unit: Topology Comparison Based on GaN Semiconductors

Four topologies (dual active bridge, phase shift full bridge, active clamp flyback and buck+LLC) have been compared for an isolated DC-DC converter used to regulate the output power of a radio frequency generator for a gridded ion electric propulsion system for satellites. The DC-DC converter has an input voltage of 100V, being required a demanding wide output voltage regulation, 20-200V, with a maximum current of 6.5A and a maximum output power of 1.1kW. All topologies have been compared at a high switching frequency, 500kHz, to reduce the size of passive components.