Accurate switching energy estimation of parallel eGaN FETs for modern aircraft applications

Gallium Nitride (GaN) transistors will be used in converters connected to the 28V DC bus of modern aircrafts. Since the actual technology of GaN transistors deals with relatively low current (lower than 25A), a way to increase the power of converters is to either directly parallel the transistors or to parallel the commutation cells. In both approaches, accurate switching losses of the GaN transistor must be known in order to precisely design the converter. This paper shows a method for estimating independently turn-on and turn-off energies of wide bandgap devices. This method is applied to switches containing 1, 2 or 4 paralleled GaN transistors and experimental results verify the accuracy of such a method. These results are used to compare different configurations of inverters composed by GaN transistors.