| 摘要 |
PURPOSE:To discriminate a trouble mode of a thyristor switch on trouble, and to control the stoppage of the motor in consideration of the whole system by providing a current voltage detector. CONSTITUTION:A voltage commutation circuit 15 is connected to the thyristor switches 3, 4, 5, and the complete state of a short circuit is detected by detecting relays A1, A2, A3. On the other hand, the state in which detecting voltage exceeds the predetermined drop voltage of forward voltage is detected by a comparator 18 and detecting relays B1, B2, B3. The conduction or non-conduction of currents is detected by current detectors 9, 10, 11, a comparator 21 and detecting relays C1, C2, C3. The thyristor switches interrupt a gate by each trouble mode through the operation of the detecting relays A1, A2, A3, B1, B2, B3, C1, C2, C3. |
