| 摘要 |
<p>PURPOSE:To prevent shock from affecting on the generator at application of signal by converting the overexcitation control signal into a stepped on with a counter circuit before being fed to AVR. CONSTITUTION:The deviation detector 8 outputs the deviation between the allowable field current according to the internal cooling water temperature of the generator 1 and the field current. When the generator voltage is out of the normal operating range, the relay starts to work to feed the overexcitation control signal to AVR4 immediately. When it is within the normal operating range, after excessive field current continues for the first specified period, the timer 17 actuates the relay to convert the overexcitation control signal into the one rising by steps with the counter circuit before it is transmitted to AVR4. With further continuation of the excessive field current, the timer 19 actuates the relay 20 to feed the overexcitation control signal to the AVR4 directly, not through the counter circuit.</p> |
