Research and Design on Reducing the Difficulty of Magnetization of a Hybrid Permanent Magnet Memory Motor

In this article, magnetic barriers setting on both sides of a low coercive force magnet (low-Hc) and forward/reverse magnetization process of a parallel memory motor are analyzed by using magnetic circuit method and finite element analysis (FEA). The results show that magnetic barriers on both sides of the low-Hc magnets can weaken the influence of high coercive force magnets (high-Hc) on the low-Hc magnets and improve anti-demagnetization ability of the low-Hc permanent magnets. At the same time, the motor has difficulties in forward magnetization. In order to reduce the difficulty in magnetization of the motor, a new type of parallel hybrid permanent magnet memory motor is proposed. The structure and the operation principle of the motor are elaborated in detail in the paper. The analysis results by using the magnetic circuit method and FEA show that the new structure can greatly reduce the magnetization current of the motor. Compared with the existing parallel hybrid permanent magnet memory motor, the improved motor has comparatively less difficulty in magnetization and stronger anti-demagnetization ability. Finally, a prototype is fabricated and the magnetization performance and efficiency of the motor is verified. The measured results show that the motor has advantages of low magnetizing current and high efficiency.