Permanent Magnet Eddy Current Analysis of SPM Synchronous Motors according to Magnet Shapes

  • Lee, Sun-Kwon (Korea Marine Equipment Research Institute) ;
  • Kang, Gyu-Hong (Korea Marine Equipment Research Institute) ;
  • Kim, Byoung-Woo (School of Electrical Engineering, University of Ulsan) ;
  • Hur, Jin (School of Electrical Engineering, University of Ulsan)
  • Received : 2014.10.27
  • Accepted : 2014.11.18
  • Published : 2014.12.01


This paper presents the comparison study of permanent magnet (PM) eddy current of concentrated winding type surface permanent magnet synchronous motor (SPMSM) with different rare-earth magnet shapes. The fractional slot winding having 10 poles and 12 slots is studied. The PM eddy current is analyzed to compare for each shape by 2 dimensional (2D) finite element analysis (FEA). The eddy current and their loss of particular position of PM as well as their distributions are displayed for each model. The effect of partly enlarged air-gap made by PM shape to PM eddy current is compared.


  1. S. K. Lee, G. H. Kang, and J. Hur, "Finite element computation of magnetic vibration sources in 100kW two fractional-slot interior permanent magnet machines for ship", IEEE Trans. Magn., vol. 48, no. 2, pp. 867-870, 2012.
  2. Z. Q. Zhu, D. Ishak, D. Howe, and J, Chen, "Unbalanced magnetic forces in permanent-magnet brushless machines with diametrically asymmetric phase windings", IEEE Trans. Ind. Appl., vol. 43, no. 6, pp. 1544-1553, 2007.
  3. K. Yamazaki, and Y. Fukushima, "Effect of eddy-current loss reduction by magnet segmentation in synchronous motors with concentrated winding", IEEE Trans. Ind. Appl., vol. 47, no. 2, pp. 779-788, 2011.
  4. K. Yamazaki, M, Shina, Y, Kanou, M, Miwa, and J, Hagiwara, "Effect of eddy current loss reduction by segmentation of magnets in synchronous motors : difference between interior and surface types", IEEE Trans. Magn., vol. 45, no. 10, pp. 4756-4759, 2009.
  5. J. Wang, K. Atallah, R. Chin, W. M. Arshad, and H. Lendenmann, "Rotor eddy-current loss in permanent-magnet brushless AC machines", IEEE Trans. Magn., vol. 46, no. 7, pp. 2701-2707, 2010.
  6. J. H. Seo, D. K. Woo, T. K. Chung, and H. K. Jung, "A study on loss characteristics of IPMSM for FCEV considering the rotating field", IEEE Trans. Magn., vol. 46, no. 8, pp. 3213-3216, 2010.
  7. K. Yamazaki, and Y. Fukushima, and M. Sato, "Loss analysis of permanent-magnet motors with concentrated windings-variation of magnet eddy-current loss due to stator and rotor shapes", IEEE Trans. Ind. Appl., vol. 45, no. 4, pp. 1334-1342, 2009.
  8. T. Okitsu, D. Matsuhashi, Y. Gao, and K. Muramatsu, "Coupled 2-D and 3-D eddy current analyses for evaluating eddy current loss of a permanent magnet in surface PM motors", IEEE Trans. Magn., vol. 48, no. 11, pp. 3100-3103, 2012.
  9. S. H. Han, W. L. Soong, T. M. Jahns, M. K. Guven, and M. S. Illindala, "Reducing harmonic eddy-current losses in the stator teeth of interior permanent magnet synchronous machines during flux weakening", IEEE Tran. Eng. Convs., vol. 25, no. 2, pp. 441-449, 2010.
  10. Y. Kuang, J. Dong, J. Zhu, and Y. Guo, "Core loss modeling for permanent-magnet motor based on flux variation locus and finite-element method", IEEE. Magn., vol. 48, no. 2, pp1023-1026, 2012.
  11. L. Ye, D. Li, Y, Ma, and B. Jiao, "Design and performanceof a water-cooled permanent magnet retarder for heavyvehicles", IEEE Trans. Eng. Convs., vol. 26, no. 3, pp. 953-958, 2011.

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