Power Electronics and Motor Drive Systems

10.4. Gate Turn-Off Thyristor (GTO)

The gate turn-off thyristor (GTO) is a type of thyristor that turns on with the same way as a conventional thyristor but in contrast turns off by applying a negative voltage between the gate and the cathode (i.e., negative gate current i_g). The negative gate current is dependent to the current to be turned off. The conventional thyristor is naturally commutated and the GTO is forced commutated. Fig. 10.37(a) shows all the possible symbols of a GTO, Fig. 10.37(b) shows its cross section and Fig. 10.37(c) shows its equivalent operation circuit. Like a thyristor, a GTO is also a four layer three junction p–n–p–n device with the outside p layer providing the anode connection, and the outside n layer providing the ...