Dynamic Characteristic Analysis of Irreversible Demagnetization in SPM- and IPM-Type BLDC Motors

In this study, the dynamic characteristic analysis algorithm is developed for the irreversible demagnetization. The conventional static characteristic analysis of irreversible demagnetization considers only the d-axis magnetic flux components. However, the accuracy of this method is limited in its analysis of the characteristics of the irreversible demagnetization when the motor is rotating. Therefore, we have developed a dynamic characteristic analysis algorithm for irreversible demagnetization. Using the developed algorithm, static and dynamic characteristic analysis of irreversible demagnetization is compared for interior- and surface-type permanent magnets brushless dc motor. Finally, we propose a maximum current limit for motor designs to reduce the impact of irreversible demagnetization.