Hubei motor manufacturer-Wanbang Motor reminds that, for ordinary low-voltage motors, the main factors affecting the winding insulation life are machine stress, fever and short-term overcurrent impregnation.For high-power and high-voltage motors, the main reason that affects the insulation life of the windings, in addition to the above factors, another more important factor is the partial discharge of the windings.

　　When dealing with high-power high-voltage motors with voltage levels of 3kV/6kV and above, partial discharges are likely to occur inside and outside the insulation.According to statistics from Hubei Wanbang Motor Factory, the damage of high-power and high-voltage motors close to 50% is caused by damage to the stator winding insulation, and most of the damage to the winding insulation is caused by partial discharge.Therefore, the measurement and prevention of partial discharge in high-power and high-voltage motors have been valued by all Hubei motor manufacturers and motor utilization customers. Partial discharge testing has gradually been used to control the quality of motor insulation and evaluate the reliability of operation.

　　High-power and high-voltage motor windings are less obstructive when the motor is running normally, mostly when the motor starts and brakes frequently, overloads, and the momentary overvoltage and overcurrent are generated when the brake is started.Obstructive parts are mostly generated between the turns of the winding, the coil lead (the circle directly adjacent to the lead), the end notch, and between the end coil and the end ferrule.

　　The following are the reasons why Hubei Wanbang motor manufacturer clarified and organized the hindering partial discharge of high-power and high-voltage motors:

　　XNUMX. Interlayer insulation hindered by high-power and high-voltage motors

　　This problem occurs in the core groove, which mainly refers to the two-phase coil in the same groove; the general problem includes the material of the interlayer spacer is not good, and the thickness is thin; the interlayer spacer is offset and the size does not match, such as too Narrow, insufficient length; loose coils cause wear of interlayer pads, etc.

　　XNUMX. Inter-turn insulation breakdown of high-power high-voltage motor coils

　　The problem is probably caused by the coil manufacturing link and the motor utilization link caused by the loosening of the coil, the wear of the interlayer gasket, the loss of the inter-turn insulation during the coil construction process, the insufficient thickness of the inter-turn insulation or the layout Injustice and other unsuitability issues.To deal with high-voltage motors, the quality of the magnet wire itself, the process of manipulation such as winding, forming and other processes that cause damage to the magnet wire is a problem that cannot be ignored.

　　Three, high-power motor windings obstruct the ground

　　If the motor is permanently overloaded, it is easy to cause insulation degradation and insulation to ground breakdown; over-voltage operation will cause the motor windings to burn and break the insulation; for synchronous motors, when the excitation coil is suddenly disconnected, high voltage breakdown of the coil will occur. Insulation to the ground; when the electric operation is bad, the creepage interval is reduced due to the conductive dust, and breakdown or flashover occurs to the ground; the motor iron core ventilation duct gasket, the tooth pressure plate is welded or the rivet is damaged, and the iron core is not tightly stacked. Problems such as trembling and bending of the teeth wear out the coil insulation; the insulation after being subjected to mechanical and electromagnetic forces cracks or suffers damage, etc.