Design and analysis of a novel hybrid permanent magnet memory motor

In this paper, a novel hybrid permanent magnet memory motor is proposed. NdFeB magnets are used to produce basic rotor magnetic field and ferrite magnets are employed to enhance or weaken rotor magnetic field. The magnetization strength and direction of ferrite can be controlled by stator d-axis current pulse. As a result, the rotor magnetic field can be adjusted, which results in the expansion of the operation range. Using the finite element method, the magnetic characteristics and design methodology of the proposed motor are studied and analyzed. A prototype is fabricated and the experimental results have verified the theoretical analysis.