Investigation on the switching property of IGCT used in large power voltage source inverter

The integrated gate commutated thyristors (IGCTs) have the features of high current, high voltage, high reliability, compact structure and low loss. They have been widely used in large power voltage source inverter systems now, and they have extensive application prospect. In the paper, the performance of IGCT and diode is introduced. With the function models of IGCT and diode, the switching property of IGCT used in large power voltage source inverter is investigated. And part of the simulation results are verified with experiment results. During the turn-on process of IGCT, over current through it will appears for the reverse recovery of the fly-wheel diode. During the turn-off process of IGCT, over voltage over it will appear for the existence of the stray inductance and the clamp inductance. The property of the snubber diode and the parameters of the circuit will also influence the turn-off process of the IGCT. In order to ensure the performance reliability, the parameters of the diode and the circuit should be carefully chosen.