If the wind temperature of the generator is too high, the temperature of the stator coil and iron core will increase accordingly, causing the insulation to become embrittled and lose its mechanical strength, greatly shortening the life of the generator. In severe cases, it will cause damage to the insulation of the generator. Breakdown causes accidents.
If the wind temperature is too low, it will cause hydrogen gas to condense and leak, causing water droplets to condense on the generator coil, reducing its insulation ability and causing damage to the generator. Therefore, the wind temperature of the generator must be maintained within the range specified by the regulations during normal operation.
The insulation grade of the generator stator winding and iron core is F, and the maximum temperature shall not exceed the limit temperature of 105°C.
During rated operation of the generator, the temperature range of the stator winding and iron core is between 60℃-80℃.
Extended information:
Regulations on generator temperature and temperature rise:
1. The bearing outlet oil temperature shall not exceed 65℃ , the bearing temperature does not exceed 80℃.
2. The air temperature at the inlet of the generator shall not be lower than 20℃, the maximum shall not exceed 55℃, and the temperature difference between the two sides shall not be greater than 3℃.
3. When the generator inlet air temperature is between +40℃ and +45℃, for every 1℃ increase, the allowable value of the stator current will be reduced by 1.5% compared with the rated value. ?
4. When the inlet air temperature is +45℃, the apparent power of the generator should be reduced by 7.5%.
5. When the inlet air temperature is between +45℃ and +50℃, for every 1℃ increase, the allowable value of the stator current is reduced by 2% from the rated value.
6. When the inlet air temperature is between +50℃ and +55℃, the allowable value of the stator current is reduced by 3% from the rated value for every 1℃ increase.
7. The maximum air temperature at the generator inlet should not exceed 55°C. If it exceeds, measures should be taken to reduce the active and reactive loads of the generator. If this does not work, please consult the chief engineer.
8. When the generator inlet air temperature is lower than the rated value, the allowable stator current will increase by 0.5% from the rated value for every 1°C decrease. At this time, the rotor current is also allowed to increase accordingly, but The generator is only allowed to increase until the inlet air temperature is +10% lower than the rated value. If the inlet air temperature drops further, the current value shall not increase any further.
9. The air temperature difference between the outlet and inlet of the generator should generally not be greater than 25°C. If it exceeds 25°C, the cause should be found.
10. Under normal circumstances, the water temperature at the inlet of the air cooler should not exceed 20℃ and should not be lower than 5℃, or the air cooler should not contain condensation.
11. The maximum air temperature at the generator outlet shall not exceed 70℃.
Baidu Encyclopedia-Insulation Level