Study On Failure Signal Processing Of Induction Motor And Software Realization

Electromotors are widely used in the modern industry and the normal living, and many researches have been investigated about the theory and method of on-line detection of rotor fault in induction motors. In this paper, based on the works previously, the type of the fault and the method of diagnosis in induction motors are summarized, and a diagnostic system of the fault about induction motor is developed.The general faults of electromotor are turn-to-turn short in winding of stator and rotor, earth connection in winding, broken-bar in rotor, collapsing in end ring, and air-gap eccentricity. The common diagnosis methods of rotor fault are mainly based on the parameters estimated methods and based on the signal analysis methods that include stator current analysis, induction voltage analysis, torque and harmonic analysis, axial magnetic flux and axial vibration diagnosis, rotational speed detection and the model classifications. Above all, the method of current analysis is used most widely.In the fault diagnosis detection technologies, the key issues are to analysis and extract the fault signals, which are directly related to the veracity of fault diagnosis and the reliability of trouble prediction. So, in the broken rotor analysis methods, the adaptive filtering and the digital filtering based on Hilbert analytical methods used to increase the ratio of the Signal-to-Noise. From the presentation of references, it is showed that the adaptive filtering analysis method needs huge calculation. So the digital filter analytical method based on Hilbert transformation is adopted in our systerm. And the examination results have testified that the method can satisfy the requirement of the fault diagnosis of broken bars in motor's rotor.