Potential of RC-IGBTs in three level converters for wind energy application

At medium voltage level the three level NPC converter is commonly used. As generator side converter in wind energy applications the diodes are most stressed and limit operation. The BIGT combines the functionality of the IGBT and the free-wheeling diode in one chip. The larger usable chip area in both IGBT and diode mode decreases the maximum junction temperature as well as the junction temperature ripple compared to a conventional IGBT/diode module at the same output power. This leads to reduced power cycling stress and improved lifetime. A lower maximum junction temperature enables an increase in output power. The potential of the BIGT in the NPC converter for wind energy applications is investigated and compared to the conventional IGBT/diode module for a real wind speed over time profile measured at FINO 1 station in the German North Sea.