Magnetic Gearing as a Functional Principle in Electric Drives

Abstract:

The partitioned stator flux reversal machine (PS-FRPM) is a novel stator PM machine topology, which exhibits a higher torque capability than its single stator counterpart and the conventional permanent magnet synchronous machine (PMSM). The PS-FRPM consists of two stators, one which carries the armature winding, and one which is equipped with surface mounted permanent magnets. The rotor is sandwiched between the two stators. The separation of the stator allows a better utilization of the machine volume which results in a higher torque density. Furthermore, because the magnets are placed on a stationary component, they can be cooled effectively. Consequently, critical rare-earth materials can be saved.The structure of the PS-FRPM is very similar to that of magnetic gears. In this paper the torque production of a PS-FRPM is described by means of the magnetic gearing effect. First the magnetic gearing effect is introduced and then the corresponding analytics is transferred to the PS-FRPM. Based on Maxwell's stress tensor, the torque contributions of the individual space harmonics are determined. In contrast to conventional machines, the torque in PS-FRPM is produced by several space harmonics in both air gaps.

• Periodical: Applied Mechanics and Materials (Volume 882)
• Pages: 162-173
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.882.162
• Online since: July 2018
• Authors: Tobias Gerlach, Rolf Vollmer, Andreas Kremser, Dieter Gerling
• Keywords: Magnetic Gear, Magnetic Gearing Effect, Magnetically-Geared Machine, Partitioned Stator, Permanent Magnet Machine, Stator-PM Machine

References

[1] M. Cheng, W. Hua, X. Zhu, X. Kong, J. Zhang, and W. Zhao, Stator-permanent magnet brushless machines: Concepts, developments and applications,, International Conference on Electrical Machines and Systems (ICEMS), pp.2802-2807, (2008).

DOI: 10.1109/icems.2019.8921792

[2] S. E. Rauch and L. J. Johnson, Design principles of flux-switch alternators [includes discussion],, Transactions of the American Institute of Electrical Engineers. Part III: Power Apparatus and Systems, vol. 74, no. 3, (1955).

DOI: 10.1109/aieepas.1955.4499226

[3] Y. Liao, F. Liang, and T. A. Lipo, A novel permanent magnet motor with doubly salient structure,, in Conference record of the 1992 IEEE Industry Applications Society Annual Meeting. New York and Piscataway, NJ: Institute of Electrical and Electronics Engineers, 1992, pp.308-314.

DOI: 10.1109/ias.1992.244279

[4] C. Wang, S. A. Nasar, and I. Boldea, Three-phase flux reversal machine (frm),, IEE Proceedings - Electric Power Applications, vol. 146, no. 2, p.139, (1999).

DOI: 10.1049/ip-epa:19990114

[5] E. Hoang, A. H. Ben-Ahmed, J. Lucidarme, Switching flux permanent magnet polyphased machines,, Proc. Eur. Conf. Power Electron. Appl., pp.903-908, (1997).

[6] M. Cheng, W. Hua, J. Zhang, and W. Zhao, Overview of stator-permanent magnet brushless machines,, IEEE Transactions on Industrial Electronics, vol. 58, no. 11, pp.5087-5101, (2011).

DOI: 10.1109/tie.2011.2123853

[7] W. Hua, Z. Q. Zhu, M. Cheng, Y. Pang, and D. Howe, Comparison of flux-switching and doubly-salient permanent magnet brushless machines,, in Proceedings of the Eighth International Conference on Electrical Machines and Systems, 2005, ICEMS 2005, M. Cheng, Ed. Beijing: Internat. Academic Publ. World Publ. Corp, 2005, pp.165-170.

DOI: 10.1109/icems.2005.202506

[8] J. Zhang, M. Cheng, Z. Chen, and W. Hua, Comparison of stator-mounted permanent-magnet machines based on a general power equation,, IEEE Transactions on Energy Conversion, vol. 24, no. 4, pp.826-834, (2009).

DOI: 10.1109/tec.2009.2025346

[9] W. Hua, M. Cheng, Z. Q. Zhu, W. Zhao, and X. Kong, Comparison of electromagnetic performance of brushless motors having magnets in stator and rotor,, Journal of Applied Physics, vol. 103, no. 7, p. 07F124, (2008).

DOI: 10.1063/1.2838222

[10] Pang, Y., Zhu Z. Q., Howe D., Iwasaki S., Deodhar R., Pride A., Comparative study of fluxswitching and interior permanent magnet machine,, Proceeding of International Conference on Electrical Machines and Systems, vol. 2007, (2007).

DOI: 10.1109/icems12746.2007.4412185

[11] A. Thomas, Z. Q. Zhu, G. W. Jewell, and D. Howe, Flux-switching pm brushless machines with alternative stator and rotor pole combinations,, Journal of Asian Electric Vehicles, vol. 6, no. 1, pp.1103-1110, (2008).

DOI: 10.4130/jaev.6.1103

[12] J. T. Chen, Z. Q. Zhu, S. Iwasaki, and R. P. Deodhar, Influence of slot opening on optimal stator and rotor pole combination and electromagnetic performance of switched-flux pm brushless ac machines,, IEEE Transactions on Industry Applications, vol. 47, no. 4, pp.1681-1691, (2011).

DOI: 10.1109/tia.2011.2155011

[13] Chen, J. T. and Zhu, Z. Q. and Iwasaki, S. and Deodhar, R. P., A novel e-core switched-flux pm brushless ac machine,, IEEE Transactions on Industry Applications, vol. 47, no. 3, pp.1273-1282, (2011).

DOI: 10.1109/tia.2011.2126543

[14] Z. Q. Zhu, J. T. Chen, Y. Pang, D. Howe, S. Iwasaki, and R. Deodhar, Analysis of a novel multitooth flux-switching pm brushless ac machine for high torque direct-drive applications,, IEEE Transactions on Magnetics, vol. 44, no. 11, pp.4313-4316, (2008).

DOI: 10.1109/tmag.2008.2001525

[15] J.-X. Shen and W.-Z. Fei, Permanent magnet flux switching machines - topologies, analysis and optimization,, in Fourth International Conference on Power Engineering, Energy and Electrical Drives (POWERENG), 2013. Piscataway, NJ: IEEE, 2013, pp.352-366.

DOI: 10.1109/powereng.2013.6635633

[16] Z. Q. Zhu and D. Evans, Overview of recent advances in innovative electrical machines - with particular reference to magnetically geared switched flux machines,, in 17th International Conference on Electrical Machines and Systems (ICEMS), 2014. Piscataway, NJ: IEEE, 2014, pp.1-10.

DOI: 10.1109/icems.2014.7013921

[17] D. J. Evans, Z. Q. Zhu, Z. Z. Wu, H. L. Zhan, and X. Ge, Comparative analysis of parasitic losses in partitioned stator switched flux pm machines with double- and single-layer windings,, in IEEE International Electric Machines and Drives Conference (IEMDC). Piscataway, NJ: IEEE, 2015, pp.167-173.

DOI: 10.1109/iemdc.2015.7409055

[18] Z. Q. Zhu, Z. Z. Wu, D. J. Evans, and W. Q. Chu, Novel electrical machines having separate pm excitation stator,, IEEE Transactions on Magnetics, vol. 51, no. 4, pp.1-9, (2015).

DOI: 10.1109/tmag.2014.2358199

[19] Z. Q. Zhu, H. Hua, Di Wu, J. T. Shi, and Z. Z. Wu, Comparative study of partitioned stator machines with different pm excitation stators,, IEEE Transactions on Industry Applications, vol. 52, no. 1, pp.199-208, (2016).

DOI: 10.1109/tia.2015.2477055

[20] K. Atallah, S. D. Calverley, and D. Howe, Design, analysis and realisation of a highperformance magnetic gear,, IEE Proceedings - Electric Power Applications, vol. 151, no. 2, p.135, (2004).

DOI: 10.1049/ip-epa:20040224

[21] P. O. Rasmussen, T. O. Andersen, F. T. Jorgensen, and O. Nielsen, Development of a highperformance magnetic gear,, IEEE Transactions on Industry Applications, vol. 41, no. 3, pp.764-770, (2005).

DOI: 10.1109/tia.2005.847319

[22] L. L. Wang, J. X. Shen, P. Luk, W. Z. Fei, C. F. Wang, and H. Hao, Development of a magneticgeared permanent-magnet brushless motor,, IEEE Transactions on Magnetics, vol. 45, no. 10, pp.4578-4581, (2009).

DOI: 10.1109/tmag.2009.2023071

[23] Q. Wang, S. Niu, and S. Yang, Design optimization and comparative study of novel magneticgeared permanent magnet machines,, IEEE Transactions on Magnetics, vol. 53, no. 6, pp.1-4, (2017).

DOI: 10.1109/tmag.2017.2662947

[24] Z. Z. Wu and Z. Q. Zhu, Analysis of magnetic gearing effect in partitioned stator switched flux pm machines,, IEEE Transactions on Energy Conversion, vol. 31, no. 4, pp.1239-1249, (2016).

DOI: 10.1109/tec.2016.2590988

[25] H. O. Seinsch, Oberfelderscheinungen in Drehfeldmaschinen: Grundlagen zur analytischen und numerischen Berechnung [Space harmonics in electrical machines: Fundamentals of analytic and numeric calculations]. Stuttgart: Teubner, (1992).

[26] M. Scheidt, Entwurfskriterien für permanentmagneterregte Synchronmaschinen in Zahnspulentechnik unter besonderer Berücksichtigung der Zusatzverluste [Design criteria for permanent magnet synchronous machines having tooth coil windings with special consideration of additional losses], ser. Kaiserslauterer Beiträge zur Antriebstechnik. Aachen: Shaker, 2009, vol. Bd. 3.

[27] G. Müller and B. Ponick, Theorie elektrischer Maschinen [Theory of electric drives], 6th ed., ser. Elektrische Maschinen. Weinheim: Wiley-VCH, (2009).

DOI: 10.1002/9783527676095.ch2

[28] C. M. Spargo, B. C. Mecrow, and J. D. Widmer, A seminumerical finite-element postprocessing torque ripple analysis technique for synchronous electric machines utilizing the air-gap maxwell stress tensor,, IEEE Transactions on Magnetics, vol. 50, no. 5, pp.1-9, (2014).

DOI: 10.1109/tmag.2013.2295547