| 摘要 |
PURPOSE:To suppress the output voltage of a generator from increasing just after an electric power system is breaked, by monitoring the change of an exciting current generated when the electric power system is breaked or a system current is changed rapidly, and by sensing the break or rapid change of a load, and by restricting the exciting current of a secondary winding which is synthesized in such manner as a vector. CONSTITUTION:At a time t1, a deviation I of a sensed value If of an exciting current, which is reduced owing to an armature reaction, from a command value I2 of the exciting current, exceeds a fixed value. This is sensed by a comparator 27, and thus, the break of a load is sensed. Thereby, a change-over switch 55 cams into ON-state, and from a compensating circuit 54, its output Ic= I is outputted. By a subtracter 50, the output Ic (= I) is subtracted from the command value I2 of the exciting current. Accordingly, the input current value to a subtracter 51 is nearly equalized to the sensed value If of the exciting current. As a result, the deviation I comes into about zero, and the output of a current control computing element 23 itself is not changed too. Thereby, the sensed value If of the exciting current is restricted too, and a generator voltage VG is suppressed from increasing rapidly. |
