The effects of a generator overload on the turbine include broken blades, overcurrent in the generator and possible burnout.
Hydraulic generator sets must not be overloaded during normal operation. The operating rules stipulate that the generator can withstand short-term overload in the event of an accident, because the generator has limited resistance to temperature increase and. the temperature resistance of the insulating material There is a certain margin, so short-term overload has little effect on the life of the insulating material. There is an aging process of the winding insulation. The insulating material becomes brittle, dielectric damage increases. and the breakdown voltage resistance decreases, etc., all of which require high temperature effect time. The shorter the high temperature exposure time, the higher the admissible current value of the generator forshort-term overload is slight. must comply with the manufacturer's instructions.
The generator is defective.
Common generator faults and measurements:
1. Common Generator Faults
1 Generators are not parallel in the same period.
2. The generator temperature increases.
3. Generator stator winding is damaged
4. The generator rotor winding is grounded
2. Measures in the event of generator failure
1. the generators are put in parallel using the quasi-synchronous method, they must meet the three conditions of the same voltage, frequency and phase
2. When the three-phase load unbalance of the generator exceeds the allowable value, the rotor temperature will also increase. At this time, the load should be reduced immediately and efforts should be made to adjust the system to reduce the imbalance of the three-phase load so thatthe rotor temperature drops within the allowable range.
3. If you see a fire on the generator arc, the generator relay protection device will operate immediately, causing the main switch, field switch and emergency circuit breaker to trip, and the generator will shut down to function.
4. If the rotor's two-point grounding protection device is activated, its relay will also operate. At this time, the generator's main circuit breaker must be immediately turned off to decouple the generator from the system. and stop, and at the same time turn off the de-excitation switch, set the magnetic field rheostat to the maximum resistance position, and check the rotor and excitation system after stopping.