The Application Research Of Fault Diagnosis In Variable Frequency Variable Speed Induction Motor Based On Fractional Fourier Transform

With the development of modern science and technology, and the improvement of electric degree, electric machines play a more and more important role in modern industrial plants. If the electrical machinery breaks down even to stop, not only the electrical machinery itself will encounter the damage, moreover overall system's normal operation will also come under the influence, the personal safety will be in danger, and it will create the huge economic loss. Through monitoring and analysis to the electrical machinery condition, we may go a step further being able to discover a breakdown of machine at an early date and providing against accidents worsens, reduce arises suddenly the production suspension loss which the accident creates, and create the condition for realizing the condition-overhaul.Sometimes large amount of the component changing , shortly and dashes forward sending out a character intermittently contained in diagnosis signal when malfunction appearing on electric motor, the tradition signal analysis method such as Fourier Transform can`t provide the electric motor diagnosis characteristic effectively. However, as one kind of time-frequency analyses method, Fractional Fourier Transform(FRFT) has very excellent treatment effect to linear modulate frequency(LMF).Considering the superiority of Fractional Fourier Transform(FRFT) to deal with non-stationary signals, this paper focuses on how to put Fractional Fourier Transform(FRFT) in use for the frequency conversion speed regulation asynchronous electric motor.Principle,method , priority that Fourier Transform the main body of this book has been introduced shifts have introduced Fractional Fourier Transform(FRFT) alternation to that linear modulate frequency(LMF) treatment advantage. On the basis analyzing and summing up common electric motor malfunction mechanism and its diagnosis characteristic appearing on frequency spectrum in electric current, run state two kind to frequency conversion speed regulation asynchronous electric motor stator electric current signal respectively in regular sum diagnosis lower be in progress Fractional Fourier Transform(FRFT) diagnosis characteristic draw. Fourier Transform(FRFT) the frequency conversion electric current signal that state goes down regularly two kinds with the malfunction has been carried out respectively transform, draw out of to diagnosis characteristic frequency channel, detailed contrast the characteristic frequency channel drawing regularly when the diagnosis works has been carried out, on the oscillogram from characteristic frequency channel weight re-structure signal it can be seen electric motor diagnosis, extracting owing to the characteristic that Fractional Fourier Transform(FRFT) method to be able to superficial characteristics having effect.