Fault Detection by Means of Hilbert–Huang Transform of the Stator Current in a PMSM With Demagnetization

摘要

This paper presents a novel method to diagnose demagnetizationudin permanent-magnet synchronousmotor (PMSM).udSimulations have been performed by 2-D finite-element analysis inudorder to determine the current spectrum and the magnetic fluxuddistribution due to this failure. The diagnostic just based on motorudcurrent signature analysis can be confused by eccentricity failureudbecause the harmonic content is the same. Moreover, it canudonly be applied under stationary conditions. In order to overcomeudthese drawbacks, a novel method is used based upon theudHilbert–Huang transform. It represents time-dependent series in aud2-D time–frequency domain by extracting instantaneous frequencyudcomponents through an empirical-mode decomposition process.udThis tool is applied by running the motor under nonstationaryudconditions of velocity. The experimental results show the reliabilityudand feasibility of the methodology in order to diagnose the demagnetizationudof a PMSM.