An asynchronous motor rotor broken bar fault on-line diagnosis method

Abstract

This invention discloses an online diagnostic method for rotor bar breakage faults in asynchronous motors, relating to the field of fault diagnosis. The method includes: Step S1, acquiring one phase of the stator current of the asynchronous motor and constructing a current analysis function from the stator current; Step S2, calculating the square of the amplitude of the current analysis function, extracting and filtering the DC component of the squared amplitude, obtaining the signal after removing the DC component from the prominent fault-related AC component. Compared with existing technologies, the advantages of this invention are: This invention uses the current analysis function amplitude squared method, performing spectrum analysis after calculating the square of the analysis function amplitude and filtering out the DC component. It does not rely on the assumptions of equal amplitude and phase of both sideband components in traditional methods. Even when the amplitude and phase of the sideband components are inconsistent, it can still accurately extract the fault characteristic frequency, significantly improving the reliability and applicability of rotor bar breakage fault diagnosis.

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