Comparison of IPMSMs Using Bonded and Sintered Rare-Earth Magnets with Different Magnet Arrangements

Interior permanent-magnet synchronous motors (IPMSMs) commonly contain sintered rare-earth magnets, the use of which is disadvantageous and should be reduced. As a solution for this problem, the use of bonded rare-earth magnets in IPMSMs was investigated in this study. The purpose of this study was to design an IPMSM containing bonded magnets that can be adopted as a substitute for conventional IPMSMs containing sintered magnets. An omega-shaped magnet arrangement was proposed to improve the torque characteristics of the bonded-magnet IPMSM. In this paper, the characteristics of IPMSMs containing sintered and bonded magnets with different magnet arrangements were investigated and compared. The characteristics of the IPMSMs with omega-shaped arrangements were found to be nearly equivalent to or better than those of the conventional IPMSM.