New Measurement Method of Tj of SiCGT and Its Application to a High Voltage Inverter Operating at greater than 300°C

A new measurement method of T_j (junction temperature ), TjDM, of a SiC device installed and operated in a circuit is proposed. T_j of a SiC device has been related to the turn-off waveforms and estimated by the time in the turn-off process. T_jS of developed SiCGTs ( SiC Commutated Gate turn-off Thyristors ) under the high voltage half bridge inverter operation at 2 kHz are measured, and are confirmed to be greater than 300degC. It is demonstrated that the SiCGTs can operate in the half bridge inverter at the high voltage of 2 kV and high temperature of 315degC. Furthermore, it is shown to be able to measure real time T_j and pick up higher T_j of SiCGT compared with normal devices in the 3 phase inverter.