Inter-turn short circuit cannot be measured no matter how you measure the insulation resistance to ground, because the insulation cannot be damaged due to a short -circuit between turns. It is very simple to judge the failure of the stator and rotor. As long as the excitation part and the transmission are good, there is no-load voltage, but not high, and the power smokes, it is a stator failure. easy and there is tension, it is a rotor failure.
Generators are widely used in industrial and agricultural production, national defense, science and technology as well as daily life. There are many forms of generators, but their operating principles are all based on the law of electromagnetic induction and the law of electromagnetic induction. law of electromagnetic force. The general principle of its construction is to use magnetic materialss and electrically conductive suitable for forming magnetic circuits and circuits that conduct electromagnetic induction between them to generate electromagnetic energy and achieve the purpose of energy conversion.
Detailed informationInstallation procedures for generators:
1. Check the lubricating oil level, coolant level and fuel quantity.
2. Check the lines and joints of the diesel engine's oil supply, lubrication, cooling and other systems for oil and water leaks.
3. Check for leakage hazards such as broken skin on electrical circuits, loose ground wire electrical circuits, and firm connection between the unit and the foundation.
4. When starting the diesel generator for the first time or restarting it after a prolonged shutdown, you mustord use a hand pump to drain the air in the fuel system.
Baidu Encyclopedia - Generator
50 kW generator does not generate electricity
1 Generator overheating
(1) The generator does not operate according to the specified technical conditions. For example, the stator voltage is too high and iron loss increases; the load current is too large and the copper loss of the stator winding increases, causing the operation to slow down; speed of the cooling fan and affects the heat dissipation of the generator; power. If the factor is too low, the rotor excitation current will increase, causing the rotor to heat up. Check whether the monitoring instrument indication is normal. If this is abnormal, necessary adjustments and treatments should be made to operate the generator according to the specified technical conditions.
(2) The currentThe three-phase load of the generator is unbalanced and the overloaded single-phase winding will overheat if the difference between the three-phase current exceeds 10% of the rated current; This is a serious phase current imbalance. Unbalanced three-phase current will produce a reverse magnetic field, thereby increasing losses and causing heating of components such as pole windings and ferrules. The three-phase load must be adjusted to keep the current in each phase as balanced as possible.
(3) The air duct is clogged with dust and ventilation is poor, making it difficult for the generator to dissipate heat. Dust and grease in the air duct must be removed so that the air duct does not become clogged.
(4) The inlet air temperature is too high or the inlet water temperature is too high and the chiller is blocked. Inlet air temperatureor water should be lowered to clear the blockage in the cooler. Before the fault is cleared, the generator load must be limited to reduce the generator temperature.
(5) Too much or too little grease should be added to the bearing. Grease should be added according to regulations, generally 1/2 ~ 1/3 of the bearing chamber (the upper limit is used for). low speed, and the upper limit is used for high speed). lower limit), and must not exceed 70% of the bearing chamber.
(6) Bearing wear. If the wear is not significant, the bearing may be locally overheated; if wear is significant, the stator may be overheating; Friction with the rotor causes overheating of the stator and rotor avoidance parts. Bearings should be checked for noise. If friction between the stator and rotor is detected, the machine must be immediatelyt stopped for maintenance or replacement of bearings.
(7) The insulation of the stator core is damaged, causing a short circuit between the parts, resulting in increased local eddy current losses and heat generation. In severe cases, the stator winding will be damaged. . The machine must be stopped immediately for maintenance.
(8) The parallel wire of the stator winding is broken, causing the current of other wires to increase and generate heat. The machine must be stopped immediately for maintenance.
2. There is abnormal voltage between the neutral line of the generator and the earth
(1) Under normal circumstances, the air under each magnetic pole is caused by the influence of high order harmonics or manufacturing process. Very low voltage occurs due to uneven gaps and uneven magnetic potential. If the voltage is one to several volts, itThere is no danger and there is no need to face it.
(2) The generator winding has a short circuit or poor insulation from ground, which leads to deterioration of the performance of the electrical equipment and the generator and easily generates electricity. heat. It must be repaired in time to avoid expansion. of the accident.
(3) There is no voltage between the neutral line and earth when there is no load, but voltage appears when there is a load. This is caused by the imbalance of the three phases. the phase load must be adjusted to make it fundamentally balanced.
3. Generator current is too large
(1) The load is too large and the load should be reduced.
(2) If a phase short circuit or ground fault occurs in a transmission line, the line must be inspected and restored to normal after the fault is cleared.
4. Voltageat the generator terminals is too high
(1) The voltage of the generator parallel to the electrical network is too high. The parallel generator voltage must be reduced.
(2) The fault of the excitation device causes overexcitation, and the excitation device should be repaired in time.
5. Insufficient power
Due to insufficient compound excitation compensation of the voltage source of the excitation device, the excitation device cannot provide the required excitation current for the armature reaction , causing the voltage across the generator. be lower than the network voltage. If the rated reactive power does not exceed the rated reactive power, the following measures should be taken:
(1) Connect a three-phase voltage regulator between the generator and the excitation reactor to increase the voltage to the generator terminals and make the excitation device the magnetic potential increases graduallyent.
(2) Change the phase of the magnetomotive force of the excitation device voltage and the voltage across the generator to increase the resulting total magnetomotive force. Thousands of ohms and 10W can be connected in parallel at both ends of each phase winding. of the resistance of the reactor.
(3) Reduce the resistance of the rheostat to increase the excitation current of the generator.
It depends on how you use it, because every time you run the generator or stop it, you must first turn off the power supply (i.e. (say the knife, and some have leakage guards) to ensure that the generator generates electricity or shuts down completely. Wait for the generator to generate electricity, then push the power switch up. Because some generators are used for a long time, if you don't, it will be easye (as mentioned above). , “loss of magnetism” )! Then use a 12V battery to magnetize the generator. Just touch the positive and negative poles of the rotor slip ring (note here that if you touch them, there will be a big spark, proving that the positive and negative poles are reversed. Yes, change the positive and negative poles and touch -them if there is only a small risk, A small spark will prove that the magnetization is successful)!
Generally speaking, if the alternator group is used normally and is not not short circuited or overloaded, it will not be broken. You can check the coil for. see if it is burned. If there are burn marks, send it to the maintenance office for repair. If there are no burn marks, it means it has lost its magnetism. If the magnetization doesn't work, it's inside. the generator box. If the transistor is broken, it is better qso you can measure it yourself. If you can't do this, send it to a professional to have it measured for you (Generally speaking, the generator always vibrates a little! when it is running. (Unless you have good shockproof performance.!), check if there is a broken wire somewhere, if so, please connect it)!