Analysis on the Number of Axial Segments of Permanent Mag-net in SPMSM for Ultra-High-Speed Application

This paper describes the analysis on the Number of Axial Segments of Permanent Magnet in SPMSM for Ultra-High-Speed Application; Electric-Turbo Compound System(E-TCS) for Construction Equipment. E-TCS is a device that combines a turbocharger, which is a regenerative device through exhaust gas, and a compressor to improve the turbo lag. As a result, E-TCS must be able to drive at least 80,000 rpm and require a large torque at low speeds. And because of scattering problem of permanent magnets, so limit to increase the rotor size and shaft length is realatively long. To increase performace of motor, difficulties of permanent magnetization and reduce permanent magnet loss, the segment must be applied in the axial direction on permanent magnet. Design criteria and power loss analysis of the ultrahigh-speed motor are described by analytical method, and the results are validated by 3D-finite element method. And then, the prototype motor has been fabricated 3 cases and tested. The experimental results confrimed the validity of the proposed design and alalysis scheme of the ultra-high-speed SPMSM(Surfaced Permanent Magnet Synchronous Motor).