| 摘要 |
<p>PURPOSE:To enable operation of a generator up to the full extent of its capacity and to lessen the shock generated when an overexcitation is restricted by changing an allowable field current value in proportion to an inner-cooling gas compression and also by allowing a short period overexcitation using an integrator. CONSTITUTION:A set point for an allowable field current is obtained with a circuit 12 by adding the base quantity Vb established by setting device 11 to a voltage Vg in proportion to the inner- cooling gas compression of a generator 1 detected by a converter 10. Then the voltage of the generator 1 is detected by a converter 10. Then the voltage of the generator 1 is detected by a relay 25, and in the case where the generator voltage is above +5% and the field current is in excess of the allowable voltage, the output of a deviation detector 8 is immediately given to an AVR4 by the relay 25 which has been energized by the output of a comparator 24 through the intermediary of an arithmetic operational amplifier 39, thereby giving a restriction to the field current. In the case when the system voltage is lowered under a normal operation of the generator, the detector 13 detects that the field current exceeds a rated value, energizing a timer 14. When a contact point 15b opens after a prescribed period of time, the output of an integrator 35 which rises at an integrated speed to be determined by a resistor 32 and a capacitor 33 is applied upon the AVR4.</p> |
