What is the generator loss of excitation?
Generator loss of excitation is the disappearance of generator remanence. Remanence refers to the magnetic field retained by ferromagnetic materials when the magnetic field disappears in the process of magnetization of ferromagnetic materials. Generator residual magnetism refers to the residual magnetism retained by the stator and rotor core after shutdown.
2, why must the generator have residual magnetism?
For the self-excited generator, by generating electricity generated by the remanence, and then to the rotor winding power supply, strengthen the rotor magnetic field, through the positive feedback of the generator output voltage gradually increased, and finally reached the rated voltage. If there were no residual magnetism, the generator would not be able to generate electricity.
3. The reason of generator loss of magnetism?
1) generator is not a long time, resulting in the factory in the iron containing remanence loss, excitation winding has not established due to the magnetic field, then the generator normal operation without power, this kind of phenomenon in the long term without the unit more;
2) when the generator stops, first stop the prime mover, the diesel engine, the gasoline engine, etc., and then break the load (electric appliance), which will consume the residual magnetism in the core, thus causing the generator to lose its magnetism.
4, how to deal with generator loss of excitation?
1) disconnect the automatic voltage regulator (AVR) and the stator winding of the exciter;
2) a DC power supply with a voltage of 24V (such as a battery connected to the exciter stator winding) (note that the positive and negative poles of the battery correspond to each other);
3) start the generator set and adjust the speed to the rated speed for a period of time.