GATE CIRCUIT OF GATEETURNNOFF THYRISTOR

摘要

PURPOSE:To simplify the constitution of a gate circuit and to enhance the reliability of the gate circuit by using a thyristor as an off-driving element of an off gate circuit of a gate-turn-off thyristor. CONSTITUTION:An off gate circuit F is composed of a series circuit of a charging resistor R and an off capacitor COF which are connected across the positive terminal N and the negative terminal OL of an off power supply; a resistor 6 which is connected between the connecting point p of the resistor R and the capacitor COF and the cathode k of a gate-turn-off thyristor GTO; and a series circuit of a diode D and an off driving thyristor SOF. A diode DW for inverting polarity is connected across said capacitor COF in parallel, a series circuit of a commutating capacitor Ca and an auxiliary thyristor Sa is connected across the thyristor SOF, and a series circuit of an auxiliary reactor La and an auxiliary diode Da is connected across the thyristor Sa in inverse parallel.