Permanent magnet machines for high-speed applications

This paper overviews high-speed permanent magnet (HSPM) machines, accounting for stator structures, winding configurations, rotor constructions, and parasitic effects. Firstly, single-phase and three-phase PM machines are introduced for high-speed applications. Secondly, for three-phase HSPM machines, applications, advantages, and disadvantages of slotted/slotless stator structures, non-overlapping/overlapping winding configurations, different rotor constructions, i.e., interior PM (IPM), surface-mounted PM (SPM), and solid PM, are summarised in detail. Thirdly, parasitic effects due to high-speed operation are presented, including various loss components, rotor dynamic and vibration, and thermal aspects. Overall, three-phase PM machines have no self-starting issues, and exhibit high power density, high efficiency, high critical speed, together with low vibration and noise, which make them a preferred choice for high-performance, high-speed applications.