Abstract: At present, high-speed electric machines (HSEMs) have been widely used in many industrial fields. The  development status and future research directions of high speed motors were summarized and discussed. Firstly, the latest research progress of different types of high-speed motors was introduced, and the characteristics of various high-speed motors were summarized. Secondly, copper loss, core loss, wind and loss, and casing loss were discussed in detail. Subsequently, the application characteristics of different bearings, the research status of rotor strength and dynamic performance were introduced.Finally, through the analysis and summary on the basis of the reference literature, the problems of various high-speed motors are clarified, and the future research direction of high-speed motors is prospected.

    Key words: high speed electric machines (HSEMs); core loss; wind and friction loss; rotor strength