Application of a new 600 V GaN transistor in power electronics for PV systems

The benefits of using gallium nitride (GaN) based transistors in power electronic converters are demonstrated in this paper. The key characteristics of a new recently available normally-off GaN Gate Injection Transistor (GIT) with a blocking voltage of 600 V and a nominal drain current of 15 A are reviewed and analysed. An optimised driving circuit for low conduction and switching losses is shown. The low switching losses of the GaN GIT lead to high efficient converters with higher switching frequencies. This is demonstrated by the application of the GaN GIT in power electronic converters for photovoltaic (PV) systems (DC/DC-Converter for MPP tracking). The obtained efficiency is compared to the results with common Si devices. As freewheeling diodes Schottky diodes based on SiC and GaN are used and compared.