A 3.6 kV full SiC fuel cell boost converter for high power electric aircraft

In order to electrify commercial passenger aircrafts with several MW propulsion power, voltages in the kilovolt range are necessary. Since fuel cells show a soft output voltage characteristic, a boost converter is essential. Within this paper a 3.6 kV fuel cell DCDC-converter is presented that is based on 3.3 kV SiC-MOSFETs allowing much higher light load efficiency and switching frequency than conventional silicon IGBT solutions. The higher light load efficiency is an important feature for long haul aircrafts since the maximum power is only needed for take-off and climbing up to the cruising altitude. Within this paper, a single phase setup is built-up, the electrical design is explained and efficiency measurements are performed.