Performance comparison of a GaN GIT and a Si IGBT for high-speed drive applications

GaN power switches enable better switching characteristics compared to state-of-the-art power transistors that are widely used today. Due to their lower switching losses, GaN switches may lead to new horizons in key application areas of power electronics such as photovoltaic converters, high-speed electrical drives and contactless power transfer. However, this technology has not yet diffused fully into the industry. Therefore, today only limited experimental data is available on those switches. In this paper, a synchronous buck converter is designed using two 600 V, 15 A GaN GIT switches developed by Panasonic. Guidelines for an optimum PCB layout are given. Both electrical and calorimetric power loss measurements are shown. Finally, a comparison is made between the GIT and a similarly rated Si IGBT for high-speed electrical drive applications where the higher switching frequencies enabled by the use of GaN is shown to reduce the rotor losses in two typical types (slotted and slotless stator) of high-speed permanent-magnet electric machines.