| 摘要 |
PURPOSE:To detect the failure of breaking of a semiconductor breaking device in a high speed, by detecting that the circuit current is flowed when the interpole voltage of a main thyristor is absent. CONSTITUTION:The failure of commutation of a main thyristor 21, the failure of voltage stop or the failure of energy absorption of the main thyristor 21 or a surge absorber, a current circuit smaller than a commutating circuit current, etc. cause failures of breaking, and in any phenomenon of the failure of breaking, the circuit current is flowed under the state of no interpole voltage of the main thyristor 21. Consequently, the failure of breaking is detected in a high speed by AND among an output signal 32 (corresponding to breaking) due to a storage circuit 26 for a breaking command 31, an output signal 35 (corresponding to confirmation of the breaking operation time) due to a storage circuit 27 for the OR signal between a signal 33 of a detecting circuit 23 after the breaking command and a signal 34 of a reverse voltage detecting circuit 25 of an auxiliary thyristor 22, an inversion signal 36 (corresponding to no-voltage of the main thyristor) of the signal 33, and an output signal 37 (corresponding to presence of the circuit current). |
