High voltage motor stator coil damage problem Electrical engineers

General electrical engineer pointed out that the long-term operating experience and motor stator

winding accident phenomenon indicates that the generator and high voltage motor stator coil corrosion damage phenomenon is quite common,seriously affect the safe operation and service life of the motor.A,corrosion characteristics and parts of motor stator coil From the high voltage motor stator winding coil main insulation breakdown phenomenon,the main coil corrosion damage of the insulation can be roughly divided into two classes: class starts to coil outside the main insulation inner corrosion damage,often referred to as corrosion;Another kind began to coil internal insulation outside corrosion,commonly referred to as internal corrosion.1.1 main coil insulation outside corrosion damage (1) motor stator winding end inside the stator core and coil vibration,the primary coil insulation corrosion damage.This is the most common corrosion damage accident is also one of the most serious phenomenon.Cause this is the main reason of the corrosion damage,the motor in operation,because of its department of winding vibration under the action of electromagnetic force,the coil in the stator core groove end fixed not firm,article slot wedge,the line between layers of cushion,loose end interval block and tied the rope off,coil and lashing and friction within the interval between block,anticorona lacquer semiconductor corona corrosion damage,resulting in slot and end coil main insulation breakdown.

(2) the stator core wear corrosion of the internal magnetic materials.This kind of situation is mainly due to the maintenance process without careful cleaning and purging of the stator winding,causing the windings cracks and other corner place left some tiny

magnetic sundry,when the motor running magnetic debris was adsorbed on the surface coil insulation Lord,under the action of electromagnetic induction and electromagnetic force,magnetic impurities in rotation movement,grinding main coil insulation to drill a hole.(3) of the stator coil corrosion of

oil.At present,a large generator and high voltage motor bearing shell are widespread leak

phenomenon,thus the motor coil for burning oil corrosion accidents are quite common.Parts of the

basic focus of this kind of failure at the end of motor stator slot,winding and winding nose

leads.Are attached to the coil is characterized by the oil,to dissolve erosion effect to the main

coil insulation,main insulation and conductor is layered whole coil insulation strength is

reduced,after long time running and stator winding short circuit,grounding short circuit fault,etc. (4) the stator core silicon steel sheet of corrosion wear of the insulation.If in the process of being connected in the stator iron core,silicon steel sheet laminated,irregular or stator core ventilation channel and the end pressure refers to fixed installation,or damage to the stator core in the repair,will cause the vibration occurs when the motor running,wear insulating,eventually resulted in the breakdown of the main insulation of wire coil.1.2 coil corrosion Multiple accident statistics and fault coil autopsy results show that the coil internal corrosion is more serious.

Corrosion inside the large coil anatomic analysis showed that the corrosion is generally from insulation and conductors in the air gap between the air bubbles,coil straight line and the end of the R Angle,coil

lead off line welding etc.Corrosion phenomena within the first coil internal insulation to bleach and

gradually expand,then burning insulation form hole and a large number of green powder,so as to

accelerate and main corrosion damage of the insulation between wire strands,until the main insulation breakdown.In addition,the high temperature caused by the thermal aging is also an important factor to the internal corrosion.Second,the coil reason analysis of internal and external corrosion Motor

stator coil of the internal and external corrosion reasons,mainly due to the main coil insulation in

the motor running,long-term in electromagnetic vibration,high temperature and high voltage under the action of three kinds of factors and vibration wear,corona corrosion and thermal insulation

aging,make whole coil insulation shell,layered,burning,wear and dielectric strength reduce wait for a phenomenon,resulting in insulation breakdown of failure.Electromagnetic vibration wear corrosion (see electrical engineer) In the operation of the motor in produce all kinds of mechanical vibration,wear out coil insulation,corrosion is one of the main electromagnetic vibration on the motor end winding and the influence of notches.

If the stator core installation quality is bad,bad winding end binding process,make the coil in the groove by fixed bad,produce great vibration amplitude,article water pump interlayer pad and temperature measuring element pads in the lower level to HuiCuan move between coil and wear on the lower layer coil,the coil main insulation damage.Is more serious is that,if in the operation of the coil wire through the current 2 times frequency electromagnetic vibration,will not only make the coil and iron core and winding end interval block vibration,make the main insulation surface wear,but also can make the wire with the main insulation between the friction between interturn,shares of the wire vibration,causing wire

interturn,loose,short circuit,break between the shares.At the same time,the additional loss and the

temperature rise in short circuit,will accelerate local main insulation ageing,reduce the dielectric strength,even under normal working voltage insulation breakdown caused by failure.Therefore,the electromagnetic vibration is caused by coil outside the main insulation 8500w gasoline generatorcorrosion and the main cause of the corrosion damage.