Investigation of Demagnetization Effect on C-Shape Anisotropic Ferrite Permanent Magnet

To comprehend how a magnet is demagnetized in a diamagnetic field, it is typically necessary to directly demagnetize the magnet. However, for a magnet demagnetized by the reverse magnetic field of the coil, the demagnetization phenomenon in the middle part of the magnet is the most serious, causing the waveform of the surface magnetic flux density distribution to collapse from the middle and become a U-shaped wave. This waveform may cause vibration during motor movement, which can have a negative impact on motor stability. In this study, the operating point of the magnet can be calculated by simulation software, and the magnetic flux density of the operating point will be approximated to the measured surface magnetic flux density distribution, so that the variation of the waveform can be inferred. Through actual verification, the variation trend of the simulated waveform is consistent with that of the measured waveform, which indicates that the simulated result has a reference value and can be used as a basis for predicting whether each part of the magnet is susceptible to demagnetization in the future design and manufacture of magnets.