Comparative Study of Electromagnetic Performance of High-Speed Synchronous Motors with Rare-Earth and Ferrite Permanent Magnets

The rare-earth permanent magnet (PM) is commonly used in to improve the performance of high-speed electrical machines to compensate for their high production costs. Meanwhile, it is very likely that the demand for high-speed machines will increase in the near future as markets for new technologies continue to grow. However, a high-speed machine is required to have high performance and low manufacturing cost because mass production is needed for these applications. Therefore, in this study, a high-speed machine using a ferrite PM was designed to significantly decrease manufacturing costs. To examine the performance of the high-speed machine suggested in this paper, the performance of a high-speed model using a ferrite PM is compared with that of a SmCo PM model. A highspeed machine with a specification of 3 kW and 30,000 rpm is designed and manufactured. The designed model is analyzed using the finite element method (FEM). Finally, the no-load back-EMF in each model is examined through a back-to-back experiment.