A new gate drive circuit for high-speed operation of GTO thyristors

This paper presents a new gate turn-off drive circuit for GTO thyristors, which can accomplish faster turn-off switching for high-speed operation of the GTO. The switching characteristics of GTO´s can be improved by use of the gate drive circuit that is able to make a very high rate of the negative gate current. The major disadvantage of the conventional gate turn-off driving technique is that it has a difficulty in realizing higher negative di_G/dt due to the maximum reverse gate-cathode voltage and the stray inductances within the gate turn-off drive circuit. This paper shows that this problem can be overcome by adding another gate turn-off drive circuit to the conventional gate turn-off drive circuit. Simulation and experimental results in conjunction with chopper circuit verify the performance of the proposed gate drive circuit