A novel approach for realizing hard-driven gate-turn-off thyristor

This paper proposes a new configuration to help a GTO to achieve unity turn-off gain and snubberless turn-off capability by utilizing a series connected discrete diode. The maximum turn-off gate voltage, which is crucial for realizing a high commutation di/dt in the GTO gate loop, can be increased from about 20 V of a GTO´s gate-cathode breakdown to a voltage higher than the breakdown voltage of the added diode. The crucial issues that affect the snubberless turn-off capability of the new device are identified and analyzed. Experimental results including snubberless turn-off are also presented