1. Reasons for generator overheating:
1)
Diesel generator set
Does not operate according to specified technical conditions. For example, the stator voltage exceeds If the frequency is too high, the iron loss will increase; if the load current is too large,
stator winding
copper loss will increase; if the frequency is too low, the cooling fan speed will slow down, affecting the heat dissipation of the machine;
p>
The power factor
is too low, causing the rotor
excitation current
to increase, causing the rotor to heat up.
2) The inlet air temperature is too high or the inlet water temperature is too high,
the cooler
is blocked. The inlet air or water temperature should be lowered to clear the blockage in the cooler.
3) Bearing wear. If the wear is not serious, the bearing will overheat locally; if the wear is serious, the stator and rotor may rub against each other, causing the stator and rotor to overheat.
4) The insulation of the stator core is damaged, causing an inter-piece short circuit, causing the core to increase local eddy current loss and generate heat. In severe cases, the stator winding will be damaged.
5) The bearings are lubricated
with too much or too little grease
.
6) The parallel wire of the stator winding is broken, causing the current of other wires to increase and generate heat.
7) The three-phase load current of the diesel generator set is unbalanced, and the overloaded one-phase winding will overheat; if the difference between the three
phase currents
exceeds< /p>
10% of the rated current
is a serious phase current imbalance. The unbalanced three-phase current will produce a negative sequence magnetic field, thereby increasing losses and causing
Magnetic poles
Windings, ferrules and other components generate heat.
8) The air duct is blocked by dust and the ventilation is poor, making it difficult for the generator to dissipate heat.
2. How to deal with overheating of the generator:
1) Check whether the indication of the monitoring instrument is normal. If it is abnormal, necessary adjustments and treatments must be made to make the motor operate according to the specified technical conditions.
2) Before the fault is eliminated, the motor load should be limited to reduce the motor temperature.
3) Check the bearings for noise. If friction between the stator and rotor is found, stop the machine immediately for maintenance or replace the bearings.
4) Stop the machine immediately for maintenance.
5) Grease should be added according to regulations, usually 1/2~1/3 of the bearing chamber (the upper limit is used for low speeds, and the lower limit is used for high speeds), and the grease should not exceed 70% of the bearing chamber. % is appropriate.
6) Stop the machine immediately for maintenance.
7) The three-phase load should be adjusted to keep the current of each phase as balanced as possible.
8) Dust and grease in the air duct should be removed to make the air duct unobstructed.
What impact will the deformed fan blades on the hydrogenerator rotor have on the generator?
Heating of the motor rotor is usually caused byA fault occurred. The faults are as follows:
1. The bearing installation is unevenly stressed and the rotation is not smooth.
2. The rotor is broken.
If it is a bearing failure, the rear axle head will be repaired and then re-turned to a standard diameter, and the bearing will be processed properly.
If it is a broken rotor bar, you can start the motor and measure the current of the motor with an ammeter. If the current of the motor fluctuates high and low, then it is usually a broken rotor bar of the motor.
Extended information
The motor rotor is divided into two types: inner rotor rotation and outer rotor rotation.
The inner rotor rotates in such a way that the core in the middle of the motor is a rotating body, which outputs torque (referring to the motor) or receives energy (referring to the generator).
The external rotor rotation method uses the outer body of the motor as the rotating body. Different methods facilitate applications in various situations.
References:
The hazards of too high temperature of hydraulic turbine generator, the hazards of too high tile temperature, stator Excessive temperature of the rotor is harmful. Why install an air cooler?
The deformation of the fan blades on the rotor of the hydroelectric generator will have the following effects on the generator.
1. The motor cooling fan blades are broken, and the motor cannot dissipate effective heat. The temperature rise increases, the motor becomes hot, and the insulation aging in the stator is accelerated.
2. If the fan blades are partially damaged, it will cause unbalanced operation, the motor will vibrate, and the stability of the machine base will be damaged.
What is the reason for the overheating of the electric ball of the diesel generator set
1. Excessive stator temperature damages the insulation of the generator. The insulation temperature grade is divided into multiple groups. Hydrogen generators are generally grade F. National standards allow a temperature rise of 105 degrees. If the temperature is too high, it will damage the insulation and reduce the life of the motor. Of course, it may also directly burn out the stator coil.
2. The hazards of excessive rotor temperature are the same as the first point.
3. If the material of the bearing bush is bus alloy, the national standard cannot exceed 75 degrees, and the plastic tile is 55 degrees. If it is too high, the bearing bush will be burned and it will no longer be able to run. In actual operation, bus alloys generally operate between 40 and 60 degrees. Plastic tiles operate below 50 degrees.
4. Installing an air cooler is to cool down the stator and rotor. Water flows through the air cooler to cool the air inside the generator to achieve cooling.
Causes for overheating of the electric ball of the diesel generator set:
1) The diesel generator set does not operate according to the specified technical conditions. For example, the stator voltage is too high and the iron loss increases; the load current If the frequency is too large, the copper loss of the stator winding will increase; if the frequency is too low, the cooling fan speed will slow down, affecting the heat dissipation of the machine; if the power factor is too low,The rotor excitation current increases, causing the rotor to heat up.
2) The inlet air temperature is too high or the inlet water temperature is too high, and the cooler is blocked. The inlet air or water temperature should be lowered to clear the blockage in the cooler.
3) Bearing wear. If the wear is not serious, the bearing may be overheated locally; if the wear is serious, the stator and the rotor may rub together, causing overheating of the stator and rotor avoidance parts.
4) The insulation of the stator core is damaged, causing an inter-piece short circuit, causing the core to increase local eddy current loss and generate heat. In severe cases, the stator winding will be damaged.
5) Too much or too little grease is added to the bearing.
6) The parallel wire of the stator winding is broken, causing the current of other wires to increase and generate heat.
7) The three-phase load current of the diesel generator set is unbalanced, and the overloaded one-phase winding will overheat; if the difference between the three-phase current exceeds 10% of the rated current, it is a serious phase current imbalance. Unbalanced three-phase current will produce a negative sequence magnetic field, thereby increasing losses and causing heating of components such as pole windings and ferrules.
8) The air duct is blocked by dust and the ventilation is poor, making it difficult for the generator to dissipate heat.