What is overload? How is the generator overloaded?
1. The so-called overload means that the armature current is overloaded, but the output voltage remains unchanged. Considering that the power factor is only determined by the load, it also remains unchanged.
2. The mechanical structure must be designed according to the overload, and the main consideration is that the structural strength must be able to meet the output requirements of peak power (that is, under the maximum overload condition).
3. Data that needs to be designed according to the rated load: punching size, core stack thickness, armature and field winding data (including the number of turns and wire diameter).
4. The data that needs to be designed according to the overload: the size of the magnetic circuit is determined according to the magnetic density when overloaded, or the size of the magnetic circuit is determined according to the magnetic density when the rated load is used, but the magnetic density should have a certain margin to ensure the overload. The magnetic density of each part of the magnetic circuit does not exceed the allowable value of the magnetic circuit. The magnetic density is approximately 110% of the rated load at twice the overload. Excitation capacity is provided according to overload.
5. Other factors that need to be considered for overload are to reduce the leakage reactance of the stator (the leakage reactance will increase the internal potential, and the motor will be seriously saturated when overloaded), reduce the leakage of the rotor (the leakage will cause the rotor magnetic circuit to saturate), add Large air gap to improve overload capacity.
6. Finally, check that the temperature rise of the generator does not exceed the allowable value during the overload duration.
