Demagnetizations Diagnosis for Permanent Magnet Synchronous Motors Based on Advanced Wavelet Analysis

Permanent Magnet Synchronous Motor (PMSM) is an attractive alternative to induction machines for a variety of applications mainly because of their reliability and higher dynamic performances, adapted for emerging applications such as automotive or traction systems. In this context, diagnosing the magnets status of the motor is crucial for improving its reliability. This paper presents a new characterization of rotor faults for such a motor due to local and uniform demagnetization by means of two dimensional (2-D) Finite Element Analysis (FEA) and proposes a new non-invasive method for their detection by means of advanced Wavelet Transform (WT) of the back-EMF. Moreover, a cyclic quantification of the fault extent over time was introduced for accurate rotor fault detection.