Multidisciplinary Design Methodology for Ultra-High-Speed PM Motors

The design of ultra-high-speed PM machines requires a systematic multidisciplinary design approach to overcome the special need to consider the mutual influence of rotor dynamics, mechanical stresses, and electromagnetic aspects. To prove the effectiveness of the proposed design methodology, a 500 W, 500,000 rpm slotless PM has been calculated. The process starts by determining the initial rotor dimensions based on an air-friction loss analytical model. Then, the rotor dynamics problem has been solved using a three-dimensional finite element model, including the ball bearings suitable for ultra-high-speed applications. The radial, tangential, and axial mechanical stress analyses have been solved using an analytical model developed for the case study. Finally, the electromagnetic performance has been verified by bi-dimensional finite element models. The obtained results demonstrate the consistency of the proposed multidisciplinary design methodology.