| 摘要 |
PURPOSE:To increase a rate of rise of di/dt required for turning-off within an allowable range by using plural gate transformers connected in parallel in the output part of a turn-off gate circuit to reduce a leakage reactance while holding a dielectric strength well. CONSTITUTION:Two gate transformers 7a and 7b are used and are connected in parallel. Two gate transformers are connected in parallel in this manner to constitute the output part of the turn-off gate circuit, thereby reducing an equivalent leakage impedance of a gate rransformer circuit to a half. As the result, di/dt of a turn-off gate current and the peak value are increased, and the dielectric strength is held well. In case of a large-capacity GTO (for example, 2,500V and class 200A), 30-40A/mus is necessary for di/dt of the turn-off gate current, and a circuit which can realize easily this di/dt and is most suitable for the turn-off gate circuit of the large-capacity GTO is obtained. |
