The Research Of Asynchronous Motor Rotor Fault Diagnosis Method Based On Hilbert Transform

This paper first analyses the motor rotor broken bars,eccentric fault diagnosis technology research status and existing problems,and combining with the structure and principles of the asynchronous motor,the failure mechanism of rotor broken bars,eccentric is analyzed from the perspective of electromagnetism.It is concluded the fault feature signals of the asynchronous motor rotor broken bar,eccentric are reflected in the stator current.The theory basis is provided for the current spectrum method.Making use of the asynchronous motor stator current signal frequency spectrum analysis method to diagnose rotor fault,the broken bar and eccentricity fault characteristic frequency components in the current signal are easily affected by the fundamental frequency,making it difficult to diagnose the fault accurately.An improved method is proposed on the basis of the traditional instantaneous power signal frequency spectrum analysis method.The method uses the Hilbert transform to deal with the stator voltage and current,then the improved instantaneous power can be obtained.The improved instantaneous power signal is analyzed by signal frequency spectrum.Then according to the corresponding fault feature component in signal frequency spectrum to diagnose the rotor fault.Through constructing the asynchronous motor fault detection experimental platform to carry out a preliminary simulation experiment,the experimental results show the method does not only eliminate the influence of the fundamental component to fault feature component,but also it has more clear and concise spectrum curve.It also highlights the fault characteristic information,and weakens the other interference information.So it lays the foundation for enhancing the accuracy of diagnosing the asynchronous motor rotor broken bar and eccentricity fault.Finally,the asynchronous motor rotor fault diagnosis system is designed based on the stm32 and LabVIEW.It is laid a solid foundation for the improved instantaneous power method in the practical engineering application.