Mechanical design of rotors for permanent magnet high-speed electric motors for turbocharger applications

Mechanical design of rotors for permanent magnet high-speed electric motors for turbocharger applications

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Realisation of electrically boosted turbochargers requires electric motors capable of operating at very high speeds. These motors often use a permanent magnet rotor with the magnets retained within an interference fit external sleeve. Whilst it is possible to model such systems numerically, these models are an inefficient tool for design optimisation. Current analytical models of rotors typically consider the stresses induced by the shrink fit of the sleeve separately from the stresses generated by centripetal forces due to rotation. However, such an approach ignores the frictional interaction between the components in the axial direction. This paper presents an analytical model that simultaneously accounts for interaction between the magnet and outer sleeve in both the radial and axial directions at designed interference and with the assembly subjected to centripetal and thermal loads. Numerical models presented show that with only moderate coefficients of friction and rotor lengths; axial load transfer between magnet and sleeve takes place over a short distance at the ends of the assembly. This paper then demonstrates how the analytical model aids definition of a feasible set of rotor designs and selection of an optimum design.


    1. 1)
      • 1. Arsie, I., Cricchio, A., Pianese, C., et al: ‘A comprehensive powertrain model to evaluate the benefits of electric turbo compound (ETC) in reducing CO2 emissions from small diesel passenger cars’. SAE Technical Paper, 2014.
    2. 2)
      • 2. Keller, R., Mese, E., Maguire, J.: ‘Integrated system for electrical generation and boosting (iSGB)’. 2014 17th Int. Conf. Electrical Machines and Systems (ICEMS), 2014.
    3. 3)
      • 3. Gerada, D.: ‘High-speed electrical machines: technologies, trends, and developments’, IEEE Trans. Ind. Electron., 2014, 61, (6), pp. 29462959.
    4. 4)
      • 4. Binder, A., Schneider, T., Klohr, M.: ‘Fixation of buried and surface-mounted magnets in high-speed permanent-magnet synchronous machines’, IEEE Trans. Ind. Appl., 2006, 42, (4), pp. 10311037.
    5. 5)
      • 5. Kim, C.-K., Kim, T.-H.: ‘Finite element analysis on the strength safety of a hybrid alarm valve’, J. Manuf. Eng. Technol., 2012, 21, (2), pp. 221224.
    6. 6)
      • 6. Smith, D.J.B., Mecrow, B.C., Atkinson, G.J., et al: ‘Shear stress concentrations in permanent magnet rotor sleeves’. 2010 XIX Int. Conf. Electrical Machines (ICEM), 2010.
    7. 7)
      • 7. Gieras, J.F.: ‘Design of permanent magnet brushless motors for high speed applications’. 2014 17th Int. Conf. Electrical Machines and Systems (ICEMS), 2014.
    8. 8)
      • 8. Zhang, J., Chen, W., Huang, X., et al: ‘Evaluation of applying retaining shield rotor for high-speed interior permanent magnet motors’, IEEE Trans. Magn., 2015, 51, (3), p. 8100404.
    9. 9)
      • 9. Varaticeanu, B.D., Minciunescu, P., Fodorean, D.: ‘Mechanical design and analysis of a permanent magnet rotors used in high-speed synchronous motor’, Electroteh. Electron. Autom., 2014, 62, (1), p. 9.
    10. 10)
      • 10. Tenconi, A., Vaschetto, S., Vigliani, A.: ‘Electrical machines for high-speed applications: design considerations and tradeoffs’, IEEE Trans. Ind. Electron., 2014, 61, (6), pp. 30223029.
    11. 11)
      • 11. Abdollahi, S., Mirzaei, M., Lesani, H.: ‘Rotor optimization of a segmented reluctance synchronous motor utilizing genetic algorithm’. Int. Conf. Electrical Machines and Systems, 2009, ICEMS 2009, 2009.
    12. 12)
      • 12. Danilevich, J.B., Kruchinina, I.Y., Antipov, V.N., et al: ‘Some problems of the high-speed permanent magnet miniturbogenerators development’. ICEM 2008, 18th Int. Conf. on Electrical Machines, 2008.
    13. 13)
      • 13. Kim, S.-I., Kim, Y.-K., Lee, G.-H., et al: ‘A novel rotor configuration and experimental verification of interior PM synchronous motor for high-speed applications’, IEEE Trans. Magn., 2012, 48, (2), pp. 843846.
    14. 14)
      • 14. Smith, J.S., Watson, A.P.: ‘Design, manufacture, and testing of a high speed 10 MW permanent magnet motor and discussion of potential applications’. Proc. of the 35th Turbomachinery Symp., 2006.
    15. 15)
      • 15. Wang, T., Wang, F., Bai, H., et al: ‘Optimization design of rotor structure for high speed permanent magnet machines’. Int. Conf. on. Electrical Machines and Systems, 2007, ICEMS, 2007.
    16. 16)
      • 16. Solecki, R., Conant, R.J.: ‘Advanced mechanics of materials’ (Oxford University Press, New York, 2003).
    17. 17)
      • 17. Zhang, F., Du, G., Wang, T., et al: ‘Rotor retaining sleeve design for a 1.12 MW high-speed PM machine’, IEEE Trans. Ind. Appl., 2015, 51, (5), pp. 36753685.
    18. 18)
      • 18. Borisavljevic, A., Polinder, H., Ferreira, B.: ‘Overcoming limits of high-speed PM machines’. 2008 18th Int. Conf. on Electrical Machines, 2008.
    19. 19)
      • 19. Yon, J.M., Mellor, P.H., Wrobel, R., et al: ‘Analysis of semipermeable containment sleeve technology for high-speed permanent magnet machines’, IEEE Trans. Energy Convers., 2012, 27, (3), pp. 646653.
    20. 20)
      • 20. Li, W., Qiu, H., Zhang, X., et al: ‘Analyses on electromagnetic and temperature fields of superhigh-speed permanent-magnet generator with different sleeve materials’, IEEE Trans. Ind. Electron., 2014, 61, (6), pp. 30563063.

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