GaN-based Low-Voltage, High-Current DC-DC Converter for Aerospace Applications

Power supplies are critical to the stable operation of spacecrafts such as satellites. Currently, aerospace DC-DC converters designed for 100 V bus have been seldom studied. Due to the unique requirement of device voltage derating in aerospace applications, the converter design including topology selection and efficiency optimization under high bus voltage condition presents significant challenges. This paper focuses on a 120 W converter with an input voltage range of 70 to 120 V and a 5 V output. The space power supply was optimized through detailed modeling of different topologies. Specifically, power losses caused by PCB-winding vias at high frequency were simulated. The high-frequency via losses were mitigated by employing an interleaved layout. Finally, an experimental prototype was developed, achieving an efficiency of up to 92.4%.