Research on Magnetic-Thermal Coupling of High-Permeability Soft Magnets in SynRMs

Synchronous reluctance motors (SynRMs) without rare earths have attracted the attention of many researchers as rare earth permanent magnet materials are being consumed in large quantities and prices are increasing. In this paper, a high permeability core material, Fe-Ni alloy (1J50), is proposed for SynRMs. With the property of ultra-high permeability, it is able to increase the convex pole ratio of SynRMs at lower magnetic field intensity, thus improving the torque performance of the motors. For further validate the feasibility of 1J50 for application in SynRMs. In this paper, by building a magnetic-thermal coupling experimental setup, the coupling experiments of 1J50 and conventional silicon steel (CSS) with variable frequency and temperature are carried out. It is found that the permeability of 1J50 is higher than that of conventional silicon steel, and it is quite sensitive to high-frequency magnetic fields. The permeability of 1J50 gains an enhancement and the loss tends to decrease under high temperature conditions. The results of the study were also applied to the motor model to effectively increase the motor's reluctance torque by 15.89% and verify the feasibility of the material.