Abstract: The integrated gate commutated thyristor（IGCT）is an important element for efficient and reliable

operation of high power traction converters. The stability of high power converter system is significantly affected by

the voltage and current dynamic characteristics of the IGCT device during the turn-on and turn-off processes. The

dynamic characteristics parameters of the 4.5 kV/4 kA IGCT device were studied，which were tested under different

testing conditions. Furthermore，a numerical loss model of the IGCT device in terms of the voltage，current and

temperature was presented. The model is apt to be implemented and extended because of its simple form，and a

theoretical basis for the analysis of the loss and efficiency characteristics of the high power converter system is

established.

      Key words: integrated gate commutated thyristor（IGCT）；switching loss；dynamic characteristics；temperature characteristics