| 摘要 |
PURPOSE:To prevent the overvoltage of a GTO thyrister generated by an electromagnetic energy stored in a balance reactor by connecting an arrester to each of the parallel-connection GTO thyristors in parallel. CONSTITUTION:Let a gate turn-off time of the GTO thyristors 3, 4 be TG3, TG4 respectively and supposing of TG3<TG4, then the GTO thyristor 3 is turned off and the GTO thyristor 4 is also turned off. In this case. the voltage across the GTO thyristor 3 exceeds the limit voltage Er of the arrestor 8. Thus, a current flowing through a snubber capacitor 3C is commutated in the arrestor 8 and the maximum voltage of the GTO thyristor 3 is suppressed to the limit voltage Er of the arrestor. Similarly, the voltage of the GTO thyristor 4 exceeds the limit voltage Er of the arrestor 9, but the maximum voltage is suppressed by the limit voltage Er of the arrestor.
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