Analytical Model for Maximum Mechanical Stress Calculation of High-Speed Interior Permanent Magnet Synchronous Motors with Modified Rotor

This paper proposes an analytical model based on the equivalent centroid method to calculate the maximum mechanical stress (MMS) on the core of V-shape high-speed interior permanent magnet (IPM) motors with modified rotor. Firstly, the structure of modified rotor, which is used to reduce the core loss at high speed, is given and the analytical model for the calculation of reference stress of rotor with or without central bridge is established correspondingly. Then, an accurate function of stress concentration factor is developed to improve the accuracy of MMS of bridge from its reference stress. Finally, the calculation results are verified by both finite element analysis (FEA) and tensile experiment of electrical steel sheet and rotor core. Compared with FEA, the proposed analytical model can consume less time with the acceptable calculation accuracy, which brings convenience to the initial design and optimization of the high-speed IPM motors.