Circuit oriented simulation of GTO thyristors using bond-graphs

This paper reports on a new numerical model of GTO thyristor embedded in a buck converter configuration. The GTO thyristor and the free-wheeling diode undergo and/or generate various types of stresses which cannot appear if the switches are modelled as two-state resistors (R_ON and R_OFF), as is the case with many power circuit simulation softwares. Much more precise models have been developed from semiconductor physics, but they hardly apply to power circuit simulation because of the associated large number of equations. The purpose of this paper is to present a simple model of GTO thyristor derived from the device physics and allowing it to represent the device imperfections, in particular the behaviour at turn off. This has been achieved with the use of bond-graph technique