کنفرانس بین المللی ماشین و محرکه های الکتریکی

صفحه اصلی / The 5th International Conference on Electrical Machines and Drives

Diagnosing Partial Demagnetization and Static Eccentricity in Surface Mounted Permanent Magnet Synchronous Motor

نویسندگان :

Mahdi Nikzad¹ Zahra Nasiri-Gheidari²

1- ُSharif University of Technology 2- ُSharif University of Technology

کلمات کلیدی :

Demagnetization،Surface-Mounted Permanent Magnet Synchronous Motors (SPMSM)،Eccentricity،Finite Element Method (FEM)

چکیده :

Fault diagnosis in Surface-Mounted Permanent Magnet Synchronous Motors (SPMSMs) is crucial for ensuring operational reliability in industrial and transportation systems. Among various failure modes, demagnetization and static eccentricity faults are two of the most common and potentially destructive conditions. Both faults distort the symmetry of the air-gap magnetic field, generating similar harmonic components in the electrical signals, which makes their discrimination challenging. This paper presents a comparative analysis of these fault types using three-dimensional finite element simulations. In the demagnetization fault model, the residual flux density of one rotor magnet is reduced by different levels, while in the static eccentricity model, the air-gap length is varied to represent different eccentricity severities. Stator current waveforms were obtained for both healthy and faulty conditions and analyzed using the Fast Fourier Transform (FFT) to extract harmonic signatures and calculate the Total Harmonic Distortion (THD). The results show that while THD can indicate the occurrence of a fault, it cannot distinguish between the two fault types. To differentiate them, the 5th-to-3rd harmonic amplitude ratio should be used as a diagnostic indicator.