Generator neutral line has abnormal voltage to ground
1: Under normal circumstances, due to the influence of high harmonics or manufacturing process, the air gap under each magnetic pole is uneven and the magnetic potential is unequal, and the voltage is low. If the voltage is one to several volts, there is no danger. No need to deal with it.
2: The generator winding has short circuit or poor insulation to the ground, which causes the performance of electrical equipment and generator to deteriorate, and it is easy to generate heat. It should be repaired in time to avoid accidents.
3: Neutral line has no voltage to ground when no load, and voltage occurs when there is load. It is caused by three-phase unbalance, and the three-phase load should be adjusted to make it basically balanced.
Generator current is too large
1: If the load is too large, the load should be reduced.
2: If the transmission line is short-circuited or grounded, the line should be repaired and restored to normal after the fault is removed.
Generator terminal voltage is too high
1: The grid voltage of the generator parallel to the grid is too high, and the voltage of the parallel generator should be reduced.
2: The excitation of the excitation device causes over-excitation, and the excitation device should be repaired in time.
Insufficient power
Due to insufficient compensation of the excitation excitation of the voltage source of the excitation device, the excitation current required for the armature reaction cannot be provided, so that the generator terminal voltage is lower than the grid voltage and the rated reactive power cannot be delivered. The following measures should be taken:
1: Connect a three-phase voltage regulator between the generator and the excitation reactor to increase the voltage at the generator terminal and increase the magnetic potential of the excitation device.
2: Change the phase of the magnetomotive force of the excitation device and the voltage of the generator terminal to increase the total magnetomotive force. Several thousand ohms and 10W resistors can be connected in parallel at each end of the reactor.
3: Reduce the resistance of the varistor to increase the excitation current of the generator.
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