The damage of corona and vibration to the coil insulation of high voltage variable frequency motor

Update:25 Sep 2020

The high voltage variable frequency motor will be mecha […]

The high voltage variable frequency motor will be mechanically worn due to electromagnetic vibration, corona corrosion and heat generation due to electromagnetic vibration, high temperature and high voltage for a long time, which will cause the overall insulation of the high voltage variable frequency motor coil to peel off and layer. , Burning, abrasion, and reduced insulation strength, which eventually lead to insulation breakdown. Shandong inverter motor manufacturer-Shenghua Motor today briefly exchanged with you about the impact of corona and vibration on the coil and insulation of high-voltage inverter motor.

High voltage variable frequency motor

In the operation of the high-voltage variable frequency motor, the coil insulation is subjected to high electric field strength. If the anti-corona layer (high and low resistance band or anti-corona paint) on the insulating surface is in poor contact with the stator core, the coil will wear out if it vibrates in the slot. Surface anti-corona layer. At this time, the insulating surface has a higher potential to the iron core, causing corona discharge in the worn part, causing local instantaneous high temperature, burning and scorching the main insulation of the coil and other auxiliary insulation materials.

Corona discharge can also produce a destructive chemical reaction, which severely corrodes the insulation and coil wires, so a large amount of green powder is collected in the severely corroded parts. In addition, if the anti-corona treatment at the winding ends is not good, it will cause excessive capacitance current, causing the stator end windings to heat up, and accelerate the thermal aging and corrosion of the end winding insulation.

The vibration of the high-voltage variable frequency motor includes mechanical vibration and electromagnetic vibration. Various vibrations in the operation of the motor will wear and corrode the coil insulation. The most important one is the effect of electromagnetic vibration on the end windings and notches of the motor.

If the press-fitting quality of the stator iron core is not good, the winding end binding process is poor, and the varnishing effect is poor, the coil will vibrate in the slot due to poor fixing, and the interlayer spacer and the temperature measuring element spacer will be on the upper and lower layers. Displacement between the coils will wear the coils and damage the coil insulation.