A Hysteresis Model Based on Linear Curves for NdFeB Permanent Magnet Considering Temperature Effects

By measuring 13 grades of neodymium (NdFeB), we obtained their temperature-dependent magnetic properties from 25 °C to 120 °C. Furthermore, a piecewise linear hysteresis model for NdFeB magnet is generalized to a temperature-dependent one, where temperature coefficients are introduced to consider deterioration of magnetic performance due to rising temperature. The movement of working point on hysteresis loops when temperature changes is discussed. The model is validated by massive experimental measurement of NdFeB specimens. The accuracy of the model is about 5% in the range of 25 °C-120 °C. The proposed model can be applied in electromagnetic and thermal analysis of permanent magnet motor.