A model for the GTO thyristor during switch-off

A physical circuit-based model has been derived for the GTO during switch-off. The model simulates the electron-hole plasma and the depletion layer in the wide lightly doped base, and their relative motion, by application of the enthalpy method devised for modeling melting solids containing moving boundaries. Using this model, computations have been made of the power dissipation in a GTO thyristor during the tail phase of switch-off, in a typical snubber circuit, as a function of device parameters.