Experimental evaluation of a 1 kW, single-phase, 3-level gallium nitride inverter in extreme cold environment

Abstract

This work investigates the potential for high power density, high efficiency power conversion at extreme cold temperatures, for hybrid electric aircraft applications. A 1 kW GaN-based 3-level power converter was designed and successfully tested from room temperature down to −140 °C, using a custom milled cold-plate. Along with the first demonstration of a flying capacitor multi-level converter and associated components at such low temperature, this work characterized the effect on power conversion losses of various components as a function of temperature. A key finding is that careful attention must be paid to the passive component losses which can increase as the temperature is reduced.