Implementation, characterisation and refinement of a GTO model

The authors demonstrate the use of an equivalent circuit model for the simulation of the gate turn-off (GTO) thyristor in power electronic circuits. The equivalent circuit consists of subcircuit elements which exhibit highly nonlinear behavioural characteristics, however using the equation solving techniques available with the Saber simulator these problems are overcome. An important factor in a successful GTO model is the ability to determine easily the model parameters, ideally from the data sheet information alone. Procedures are outlined which enable this, using both direct calculations and simulator `sweep´ facilities. Finally, circuit simulation results are presented, showing switching waveforms of the GTO; V_ak, I_a, V_gk and I_g