Analysis of Demagnetization of Amorphous Alloy High-Speed Permanent Magnet Motor

Abstract

NdFeB has become the most common material for permanent magnet synchronous machines. Much research has been done on NdFeB-based permanent magnets (PMs) in the last few years (PMSMs). Although NdFeB PMs have a higher energy density and are more cost-effective than other kinds of magnets, their magnetization is very sensitive to PMSM working conditions, particularly temperature, where the irreversible demagnetization degree rises with time. As a result, it's critical to identify and diagnose demagnetization as soon as possible. This research provides a two-step analytical study dealing with uniform and partial demagnetization in this setting. A methodology based on the fast Fourier transform (FFT)-based PMSM motor current signature analysis (MCSA) is utilized to characterize demagnetization using a 2D finite element method. Subsequently, harmonics in fault instances are employed to identify demagnetization. The suggested two-step technique yielded findings identifying and characterizing demagnetization in certain cases. A local demagnetization creates particular sub-harmonics, but a uniform demagnetization increases current amplitude for a given torque.