A simple calorimetric technique for high-efficiency GaN inverter transistor loss measurement

Abstract

With the rapid development of the wide bandgap (WBG) power transistor technology, the latest Silicon-Carbide and Gallium-Nitride (SiC and GaN) based power transistors can be used as the main switches in the medium power (≥10 kW) conversion systems. Electrical signal based efficiency measurement could be very challenging due to the high-frequency output signals and the high power to loss ratio. In this paper, a new calorimetric based loss measurement method is designed to realize fast and accurate power loss measurement of WBG devices during the circuit operation. The measurement accuracy has been verified on a 10 kW, 98.8% peak efficiency GaN-based three phase inverter.