This study aims to provide a comprehensive study of various magnetic gears (MGs) with simple coaxial radial flux structure. A total of 15 topologies are first introduced, by either using various rotor structures or adding extra permanent magnets (PMs) on the magnetic modulation ring. Then, all topologies with ferrite magnets are parametrically optimised, aiming to compare and evaluate the performance of these MGs. The results show that the proposed MGs with dual consequent-pole PM rotors exhibit a higher torque density than the conventional coaxial MG. Therefore, magnetic field distribution, torque-angle characteristic and on-load torque performance of these promising MGs are analysed in detail, revealing their inherent superiorities. In addition, influence of magnet material on the MG performance are investigated with emphasis on the torque density and cost effectiveness. Finally, two MG prototypes are fabricated and tested to validate the analysis.

References

1. 1)
  - 15. Liu, X., Chau, K.T., Jiang, J.Z., et al: ‘Design and analysis of interior-magnet outer-rotor concentric magnetic gears’, J. Appl. Phys., 2009, 105, (7), p. 07F101-07F101-3 (doi: 10.1063/1.3106000).
2. 2)
  - 8. Frank, N., Toliyat, H.: ‘Analysis of the concentric planetary magnetic gear with strengthened stator and interior permanent magnet inner rotor’, IEEE Trans. Ind. Appl., 2011, 47, (4), pp. 1652–1660 (doi: 10.1109/TIA.2011.2154291).
3. 3)
  - 11. Jian, L., Chau, K.T.: ‘A coaxial magnetic gear with Halbach permanent-magnet arrays’, IEEE Trans. Energy Convers., 2010, 25, (2), pp. 319–328 (doi: 10.1109/TEC.2010.2046997).
4. 4)
  - 3. Gouda, E., Mezani, S., Baghli, L., et al: ‘Comparative study between mechanical and magnetic planetary gears’, IEEE Trans. Magn., 2011, 47, (2), pp. 439–450 (doi: 10.1109/TMAG.2010.2090890).
5. 5)
  - 16. Li, X., Chau, K.T., Cheng, M., et al: ‘A new coaxial magnetic gear using stationary permanent magnet ring’. Int. Conf. Electrical Machines and Drives, Busan, South Korea, October 2013.
6. 6)
  - 14. Peng, S., Fu, W.N., Ho, S.L.: ‘A novel high torque-density triple-permanent-magnet-excited magnetic gear’, IEEE Trans. Magn., 2014, 50, (11), pp. 1–4.
7. 7)
  - 13. Johnson, M., Gardner, M.C., Toliyat, H.A.: ‘Design comparison of NdFeB and Ferrite radial flux magnetic gears’. IEEE Energy Conversion Congress Expo., Milwaukee, USA, September 2016.
8. 8)
  - 10. Bomela, W., Bird, J.Z., Acharya, V.M.: ‘The performance of a transverse flux magnetic gear’, IEEE Trans. Magn., 2014, 50, (1), pp. 2844–2846 (doi: 10.1109/TMAG.2013.2277431).
9. 9)
  - 12. Chen, M., Chau, K.T., Li, W., et al: ‘Cost-effectiveness comparison of coaxial magnetic gears with different magnet materials’, IEEE Trans. Magn., 2014, 50, (2), pp. 821–824 (doi: 10.1109/TMAG.2013.2281988).
10. 10)
  - 2. Montague, R.G., Bingham, C.M., Atallah, K.: ‘Dual-observer-based position-servo control of a magnetic gear’, IET Electr. Power Appl., 2011, 5, (9), pp. 708–714 (doi: 10.1049/iet-epa.2011.0046).
11. 11)
  - 18. Wu, Z.Z., Zhu, Z.Q.: ‘Analysis of air-gap field modulation and magnetic gearing effects in switched flux permanent magnet machines’, IEEE Trans. Magn., 2015, 51, (5), pp. 1–12.
12. 12)
  - 7. Uppalapati, K., Bird, J., Wright, J., et al: ‘A magnetic gearbox with an active region torque density of 239 Nm/L’. IEEE Energy Conversion Congress Expo., Pittsburgh, USA, September 2014, pp. 1422–1428.
13. 13)
  - 5. Wang, L.L., Shen, J.X., Wang, Y., et al: ‘A novel magnetic-geared outer-rotor permanent-magnet brushless motor’. Proc. Int. Conf. Power Electronics, Machines and Drives, York, UK, April 2008, pp. 33–36.
14. 14)
  - 3. Atallah, K., Howe, D.: ‘A novel high-performance magnetic gear’, IEEE Trans. Magn., 2001, 37, (4), pp. 2844–2846 (doi: 10.1109/20.951324).
15. 15)
  - 9. Frank, N., Toliyat, H.: ‘Gearing ratios of a magnetic gear for marine applications’. Symp. Electric Ship Technologies, Baltimore, USA, April 2009, pp. 477–481.
16. 16)
  - 6. Uppalapati, K., Bird, J., Jia, D., et al: ‘Performance of a magnetic gear using ferrite magnets for low speed ocean power generation’. IEEE Energy Conversion Congress Expo., Raleigh, USA, September 2012, pp. 3348–3355.
17. 17)
  - 17. Shen, J.X., Li, H.Y., Hao, H., et al: ‘A coaxial magnetic gear with consequent-pole rotors’, IEEE Trans. Energy Convers., 2017, 32, (1), pp. 267–275 (doi: 10.1109/TEC.2016.2609338).
18. 18)
  - 2. Rasmussen, P.O., Andersen, T.O., Jorgensen, F.T., et al: ‘Development of a high-performance magnetic gear’, IEEE Trans. Ind. Appl., 2005, 41, (3), pp. 764–770 (doi: 10.1109/TIA.2005.847319).

Topologies and performance study of a variety of coaxial magnetic gears

References

Related content