Multi‐Objective Sleeve Optimization of Solid High Speed Permanent Magnet Motor Based on Rotor Strength Failure Judgment Parameters

Abstract It is necessary to consider the coupling effects of multiple physical fields in the rotor design of high speed permanent magnet motor. However, the calculation method ignoring axial constraints will lead to misjudgment of various strength failure modes of solid permanent magnet rotor. In this paper, the calculation methods of three kinds of judgment parameters of rotor strength failure modes under axial constraint are given by means of theoretical derivation. On this basis, a solid high speed permanent magnet motor of 38 000 rpm and 200 kW is taken as the research object to explore the rule of influence of sheath thickness on motor loss and temperature. Combining the rotor strength failure criterion and NSGAII algorithm, a new sleeve multi‐objective optimization design method for solid high speed permanent magnet motor is proposed by taking the multi‐physical properties such as strength, efficiency and temperature as objective functions. Finally, experiments and simulations are carried out to verify the effectiveness of the method. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.