The difference between the motor and the ordinary motor and constant frequency constant voltage is as follows: 1. Insulation grade: generally F grade or higher, strengthen the insulation strength of the ground insulation and the turns, especially the ability of the insulation to withstand the impact voltage.
2. Vibration and noise problems of the motor: It is necessary to fully consider the rigidity of the motor components and the whole, and try to improve the natural frequency to avoid resonance with each force wave.
3. Cooling method: Generally, forced air cooling is adopted, that is, the main motor cooling fan is driven by an independent motor.
4. Measures to prevent shaft current. For bearings with a capacity exceeding 160 kW, bearing insulation measures should be adopted. Mainly due to the asymmetry of the magnetic circuit, the shaft current is also generated. When the currents generated by other high-frequency components work together, the shaft current will increase greatly, resulting in bearing damage, so insulation measures are generally taken.
5. For constant power variable frequency motor: When the speed exceeds 3000/min, special high temperature resistant grease should be used to compensate for the temperature rise of the bearing.
