| 摘要 |
PURPOSE:To protect a thyristor exciter by interrupting a field current of an exciter when the fact that the output voltage of a thyristor exciter for supplying a field current to a field coil is the set value or lower and the output current becomes the set value or higher is detected. CONSTITUTION:A rotary electric machine 1 is excited when a field coil 2 receives the DC output of a thyristor exciter 7. A current/voltage converter 21 converts a field current to a DC voltage, and a voltage converter 22 converts the field voltage to a DC voltage. When the DC exciter shortcircuits, an exciting current increases, the negative voltage of the converter 21 increases, and the output of a comparator 25 is inverted to positive. The field voltage is decreased and the positive voltage of the converter 22 is reduced, and the output of a comparator 29 is inverted to positive. When the outputs of comparators 25, 29 become both positive, the output of the comparator 35 becomes negative, while the output of the comparator 38 becomes positive, a transistor 40 is conducted, and relays 42-44 are operated. The output of the exciter 7 is controlled to zero by the relay 42. In this manner, the controller for thyristor can be protected. |
