Bearingless switched reluctance motors (BSRMs) have both magnetic bearing as well as conventional motor characteristics which make them suitable for diverse industrial applications. This study proposes a design methodology for a BSRM in order to calculate the appropriate geometrical dimensions essential for realising a minimum levitation force at every orientation of rotor. It is based on the stator–rotor overlap angle and helps in reducing the complexities associated with the self-bearing operation of a switched reluctance motor (SRM). Different from a conventional SRM, the motor under study deploys a special single set parallel winding scheme for simultaneous production of torque as well as radial force. An analytical model incorporating this single set winding is developed for calculating the torque and the radial force. The proposed bearingless design is verified by developing a two-dimensional finite-element model of a 12/8 SRM in ANSYS Maxwell.

References

1. 1)
  - 4. Lin, F., Yang, S.: ‘Self-bearing control of a switched reluctance motor using sinusoidal currents’, IEEE Trans. Power Electron., 2007, 22, (6), pp. 2518–2526 (doi: 10.1109/TPEL.2007.909274).
2. 2)
  - 13. Chen, L., Hofmann, W.: ‘Analytically computing winding currents to generate torque and levitation force of a new bearingless switched reluctance motor’. Proc. 12th Int. Power Electronics and Motion Control Conf., Slovenia, 2006, pp. 1058–1063.
3. 3)
  - 12. Liu, W.T., Yang, S.M.: ‘Modeling and control of a self-bearing switched reluctance motor’. Proc. 14th IAS Annual Meeting, Hong Kong, 2005, pp. 2720–2725.
4. 4)
  - 18. Radun, A.V.: ‘Analytical calculation of the switched reluctance motor's unaligned inductance’, IEEE Trans. Magn., 1999, 35, (6), pp. 4473–4481 (doi: 10.1109/20.809140).
5. 5)
  - 5. Takemoto, M., Chiba, A., Akagi, H., Fukao, T.: ‘Radial force and torqueof a bearingless switched reluctance motor operating in a region of magnetic saturation’, IEEE Trans. Ind. Appl., 2004, 40, (1), pp. 103–112 (doi: 10.1109/TIA.2003.821816).
6. 6)
  - 1. Chiba, A., Fukao, T., Ichikawa, O., et al: ‘Magnetic bearings and bearingless drives’ (Newnes Elsevier, 2005).
7. 7)
  - 21. Krishnan, R.: ‘Switched reluctance motor drives: modelling, simulation, analysis, design, and applications’ (CRC Press, 2001).
8. 8)
  - 23. Radun, A.V.: ‘Analytically computing the flux linked by a switched reluctance motor phase when the stator and rotor poles overlap’, IEEE Trans. Magn., 36, (4), pp. 1996–2003 (doi: 10.1109/20.875277).
9. 9)
  - 14. Chen, L., Hofmann, W.: ‘Design procedure of bearingless high-speed switched reluctance motors’. Proc. Int. Symp. Power Electronics, Electrical Drives, Automation and Motion, Pisa, 2010, pp. 1442–1447.
10. 10)
  - 16. Morrison, C.R.: ‘Bearingless switched reluctance motor’. US Patent, US6727618 B1, April 2004.
11. 11)
  - 6. Morrison, C.R., Siebert, M.W., Ho, J.E.: ‘Electromagnetic forces in a hybrid magnetic-bearing switched-reluctance motor’, IEEE Trans. Magn., 2008, 44, (12), pp. 4626–4638 (doi: 10.1109/TMAG.2008.2002891).
12. 12)
  - 15. Chen, L., Hofmann, W.: ‘Modelling and control of one bearingless 8/6 switched reluctance motor with single layer of winding structure’. Proc. 14th European Conf. on Power Electronics and Applications, Birmingham, 2011, pp. 1–9.
13. 13)
  - 9. Wang, H., Lee, D.-H., Park, T.-H., Ahn, J.-W.: ‘Hybrid stator-pole switched reluctance motor to improve radial force for bearingless application’, Energy Convers. Manage., 2011, 52, (2), pp. 1371–1376 (doi: 10.1016/j.enconman.2010.09.035).
14. 14)
  - 7. Yuan, Y., Sun, Y., Huang, Y.: ‘Radial force dynamic current compensation method of single winding bearingless flywheel motor’, IET Power Electron., 2015, 8, (7), pp. 1224–1229 (doi: 10.1049/iet-pel.2014.0502).
15. 15)
  - 10. Chen, L., Hofmann, W.: ‘Speed regulation technique of one bearingless 8/6 switched reluctance motor with simpler single winding structure’, IEEE Trans. Ind. Electron., 2012, 59, (6), pp. 2592–2600 (doi: 10.1109/TIE.2011.2163289).
16. 16)
  - 8. Yang, Y., Liu, Z., Deng, Z., et al: ‘Design and characteristic analysis of a novel bearingless SRM considering decoupling between torque and suspension force’, Math. Probl. Eng., 2014, 2014, pp. 1–12.
17. 17)
  - 17. Khoo, W.K.S.: ‘Bridge configured winding for polyphase self-bearing machines’, IEEE Trans. Magn., 2005, 41, (4), pp. 1289–1295 (doi: 10.1109/TMAG.2005.845837).
18. 18)
  - 19. Ahmed, F., Kumar, G., Choudhury, M.D., et al: ‘Bridge configured wounded switched reluctance motor’, Proc. Eng., 2016, 144, pp. 817–824 (doi: 10.1016/j.proeng.2016.05.091).
19. 19)
  - 18. Khoo, W.K.S., Kalita, K., Garvey, S.D.: ‘Practical implementation of the bridge configured winding for producing controllable transverse forces in electrical machines’, IEEE Trans. Magn., 2011, 7, (6), pp. 1712–1718 (doi: 10.1109/TMAG.2011.2113377).
20. 20)
  - 9. Xu, Z., Lee, D.H., Ahn, J.W.: ‘Comparative analysis of bearingless switched reluctance motors with decoupled suspending force control’, IEEE Trans. Magn., 2015, 51, (1), pp. 733–743.
21. 21)
  - 20. Vijayraghavan, P.: ‘Design of switched reluctance motors and development of a universal controller for switched reluctance and permanent magnet brushless DC motor drives’. PhD thesis, Virginia Polytechnic Institute and State University, 2001.
22. 22)
  - 4. Takemoto, M., Shimada, K., Chiba, A.: ‘Design and characteristics of switched reluctance type bearingless motors’. Proc. 4th Int. Symp. Magnetic Suspension Technology, Japan, 1997, pp. 49–63.
23. 23)
  - 3. Halmeaho, T., Haarnoja, T., Manninen, A., et al: ‘Magnetic bearing as switched reluctance motor-feasibility study for bearingless switched reluctance motor’. Proc. IEEE Int. Electric Machines & Drives Conf., USA, 2013, pp. 401–408.

Design methodology for a special single winding based bearingless switched reluctance motor

References

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