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  4. Vol 9, Issue 2, 2024

Finite Element Analysis of Rotor Strength in High-Speed Permanent Magnet Generators

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DOI: 10.23977/jemm.2024.090215 | Downloads: 11 | Views: 381

Author(s)

Dongni Zhang 1

Affiliation(s)

1 CRRC Zhuzhou Electric Co., Ltd., Zhuzhou, Hunan, 412001, China

Corresponding Author

Dongni Zhang

ABSTRACT

This study systematically analyzes the stress distribution of the rotor in high-speed permanent magnet generators under different conditions, including rotor structure, types of inter-pole filler materials, sleeve thickness, interference fit, temperature, and rotational speed, using finite element analysis (FEA). The results indicate that circumferential segmentation can significantly reduce the tangential and radial stresses of the permanent magnets, with the best performance observed in the rotor structure with four segments. However, increasing the number of segments (e.g., to 20 segments) does not significantly improve the stress distribution in the sleeve and core, and in some cases, it may even exacerbate stress concentration. Regarding the choice of inter-pole filler materials, high-temperature-resistant plastic (PPS) performs best in reducing the stress on both the permanent magnets and the sleeve. Compared to carbon fiber and aluminum alloy materials, PPS more effectively reduces the stress on the permanent magnets and sleeve, especially under high-temperature and high-speed conditions, showing superior mechanical performance. Increasing the sleeve thickness effectively reduces both the tangential and radial stresses of the permanent magnets, while also decreasing the equivalent stress in the sleeve, thus enhancing the structural safety of the rotor. As the interference fit increases, the radial stress on the permanent magnets gradually decreases, while the tangential and equivalent stresses in the sleeve first increase slowly and then rapidly. When the interference fit is below 0.26 mm, the stress variation is minimal, but once it exceeds 0.26 mm, the sleeve stress increases significantly, indicating that excessive interference may lead to stress concentration and a higher risk of failure. Temperature elevation significantly increases the tangential and equivalent stresses in the permanent magnets, and the tangential and equivalent stresses in the sleeve also increase linearly with rising temperatures. At high rotational speeds, the maximum tangential stress experienced by both the permanent magnets and the sleeve increases substantially, highlighting the need for careful optimization of materials and structure in the design phase.

KEYWORDS

High-speed permanent magnet, generator, rotor, strength, finite element

CITE THIS PAPER

Dongni Zhang, Finite Element Analysis of Rotor Strength in High-Speed Permanent Magnet Generators. Journal of Engineering Mechanics and Machinery (2024) Vol. 9: 118-127. DOI: http://dx.doi.org/10.23977/jemm.2024.090215.

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