1. Adopt reasonable winding, embedding, and other processing technologies.
For variable frequency motors, the quality of Aluminum Magnet Wire and the integrity of the insulation structure have higher requirements. Therefore, the winding, embedding, binding, and other processing technologies must be strictly managed, especially in the winding and embedding process to prevent damage to wires, and the embedding process should ensure that slot insulation and phase insulation are placed in place. Phase insulation shall be made of materials that are easily soaked by insulating paint; Binding and fixing of coil ends shall be strengthened to ensure that the ends are integrated. VPI and rotary baking curing processes are also used to improve the overall mechanical strength of the insulation structure.
2. Control the length of the connecting cable from the frequency converter to the motor terminal, avoid partial discharge and prolong the service life of the motor.
As mentioned earlier, due to impedance mismatch, the overvoltage amplitude at the motor terminal increases with the increase of the length of the connecting cable, which is helpful to cause partial discharge. For this reason, manufacturers of variable frequency motors should fully understand the various variable frequency power sources used, determine the limit length of the connecting cables, and inform the users so as to reduce the overvoltage amplitude at the motor end as much as possible, avoid partial discharge, and prolong the service life of aluminum magnet wire.