Three-phase asynchronous motor fault in electrical engineer

Aiming at the need of actual production and daily maintenance and management,(see electrical

engineer) in recent electric fan motor partsyears the mechanical fault of three-phase ac asynchronous motor,motor vibration reasons were analyzed and summarized in this paper and the related characteristics of vibration monitoring value to fuzzy recognition of monitoring data,determine the monitoring equipment running status,motor running state of the ac synchron

motor failure and provide effective criterion,ensures the reliable operation of the motor.Three-phase asynchronous motor fault characteristics and diagnostic methods of motor of daily maintenance practice confirmed that the common reasons of motor fault are electromagnetic vibration,imbalance of the motor rotor,bearing wear,poor lubrication,inadequate rigidity and mechanical looseness.Run motor electrical fault can be used to measure current,electrical insulation and winding dc resistance method of judgment;Mechanical failure is often the vibration monitoring and diagnosis,the shock pulse method,the current diagnosis method and spectrum analysis,etc.According to

the motor vibration velocity standard IS02373 six points of motor in the location of the

regulation,the characteristics of the vibration acceleration,velocity and displacement amplitude,and

the use of the function of the instrument,to determine the vibration monitoring on the project for

the monitoring of vibration amplitude,speed and acceleration of high frequency value the Hi and

Lo,according to the structure of the small and medium-sized motor canceled the shaft axial stretching

end measurements.There are many uncertain factors in the process of motor running,so the fault diagnosis for its also exists certain fuzziness,mainly displays in: (1) the diagnosis parameters of fuzziness. Used for fault diagnosis of vibration parameters of the frequency range with a certain ambiguity,different parameters,the position and direction of vibration value exceeds bid,the fault

state reflected by ambiguity exists;(2) the diagnosis method of ambiguity. Causes of motor fault often is not a single,such as bearing damage,loose foundation failure often consists of

electromagnetic vibration,or dynamic imbalance caused in the wrong,so use which or what kinds of methods,a comprehensive diagnosis of fault is fuzzy;(3) the diagnostic criteria of fuzziness. Diagnostic criteria is the basis of fault diagnosis,using what kind of standard for diagnosis is relatively accurate,the operation condition changes,such as temperature,load,diagnostic www.dongfeng-motor.com criteria,how to fix all affect the accuracy of diagnosis,and there is a big ambiguity.Therefore,using the multi-parameter comprehensive analysis of the fuzzy vibration diagnosis method accord with the actual situation of motor fault diagnosis,can receive good effect.