The electric locomotives of Indian Railways currently use Gate Turn-Off Thyristors for traction drive systems. Though they are fast switching devices, they produce lot of harmonic ripples in the output voltages and currents. The snubber circuits of Gate Turn-Off Thyristors are also bulky. Comparatively, Insulated Gate Bipolar Transistors produce less harmonic ripples and also reliable fast switching devices capable of handling voltages and currents of the range 5kV and 1kA respectively. Research has also proved that, Insulated Gate Bi-Polar Transistors are also an efficient switching devices in high voltage/power applications like electric traction. The simulation studies of performance of the Squirrel Cage induction motors with Gate Turn-off Thyristors/Insulated Gate Bi-Polar Transistor as switching devices are presented in this paper.
