volume | PIER Journals

Abstract

To address the problems of torque ripple, vibration, and noise generated by cogging torque in a dual-stator single-rotor axial magnetic field permanent magnet motor, this article adopts an unequal thickness pole structure to reduce cogging torque. At first, the process of cogging torque generation is analyzed, followed by an examination of the mathematical formulation of cogging torque using the energy technique and the Fourier decomposition method. Then, the impacts of several pole optimization approaches on cogging torque reduction are then compared, and the findings are investigated using the finite element method to demonstrate the efficiency of the optimization method. The results show that the optimization effect of unequal thickness pole structure is the best. Lastly, the optimized motor's air-gap flux density, counter-electromotive force, harmonic content, and rotor mechanical strength were compared and studied to demonstrate that the unequal-thickness structure used in this research can increase motor performance. Finally, based on the determined motor parameters, experimental study of the prototype was carried out to verify the correctness of the motor structure and analysis.

1. Liu, X. P., D. Chen, M. Wang, Y. F. Huang, and Q. H. Xie, "Analysis of mechanical dynamics and flux weakening ability for a variable flux axial field permanent magnet electrical machine," Trans. Chin. Eletrotechnol. Soc., Vol. 31, 54-62, 2016. Google Scholar

2. Luo, X. and S. Niu, "Maximum power point tracking sensorless control of an axial-flux permanent magnet verneer wind power generator," Energies, Vol. 9, 581, 2016.
doi:10.3390/en9080581 Google Scholar

3. Shi, Z., X. Sun, Y. Liu, and W. Zhou, "Fault-tolerant model predictive current control of five-phase permanent magnet synchronous hub motor considering current constraints," Proceedings of the 2020 IEEE Vehicle Power and Propulsion Conference (VPPC), 1-5, Gijon, Spain, Nov. 18- Dec. 16, 2020. Google Scholar

4. Ji, J. H., Y. K. Sun, J. H. Zhu, and W. X. Zhao, "Design, analysis and experimental validation of a modular permanent-magnet machine," Trans. Chin. Eletrotechnol. Soc., Vol. 30, 243-252, 2015. Google Scholar

5. Deng, W. and S. Zuo, "Analytical modeling of the electromagnetic vibration and noise for an external-rotor axial-flux in-wheel motor," IEEE Trans. Ind. Electron., Vol. 65, 1991-2000, 2018.
doi:10.1109/TIE.2017.2736487 Google Scholar

6. Kumar, P. and R. K. Srivastava, "Influence of rotor magnet shapes on performance of axial flux permanent magnet machines," Progress In Electromagnetics Research, Vol. 85, 155-165, 2018.
doi:10.2528/PIERC18041909 Google Scholar

7. Neethu, S., S. P. Nikam, and S. Sikam, "High-speed coreless axial-flux permanent-magnet motor with printed circuit board winding," IEEE Trans. Ind. Appl., Vol. 55, 1954-1962, 2019.
doi:10.1109/TIA.2018.2872155 Google Scholar

8. Wanjiku, J., M. A. Khan, P. S. Barendse, et al. "Influence of slot openings and tooth profile on cogging torque in axial-flux PM machine," IEEE Transactions on Industrial Electronics, Vol. 62, No. 12, 7578-7589, 2015.
doi:10.1109/TIE.2015.2458959 Google Scholar

9. Gieras, J. F., R. J. Wang, and M. Kamper, Axial Flux Permanent Magnet Brushless Machines, 153-155, Springer-Verlag, 2008.
doi:10.1007/978-1-4020-8227-6_5

10. Sun, M. C., R. Y. Tang, X. Y. Han, et al. "Analysis and modeling for open circuit air gap magnetic field prediction in axial flux permanent magnet machines," Proceedings of the CSEE, Vol. 38, No. 5, 1525-1533, 2018. Google Scholar

11. Gieras, J. F., R. J. Wang, and M. Kamper, Axial Flux Permanent Magnet Brushless Machines, 29-34, Springer Verlag, 2008.
doi:10.1007/978-1-4020-8227-6_2

12. Tang, R. Y., Modern Permanent Magnet Motor: Theory and Design, 308-314, Machinery Industry Press, 1997.

13. Zhang, L., X. Y. Zhu, and Y. F. Zuo, "Overview of fault-tolerant technologies of rotor permanent magnet brushless machine and its control system for electric vehicles," Proceedings of the CSEE, Vol. 39, No. 6, 1792-1802, 2019. Google Scholar

14. Yazdani-Asrami, M., W. Song, M. Zhang, W. Yuan, and X. Pei, "Magnetization loss in HTS coated conductor exposed to harmonic external magnetic fields for superconducting rotating machine applications," IEEE Access, Vol. 9, 77930-77937, 2021.
doi:10.1109/ACCESS.2021.3062278 Google Scholar

15. Shi, Z., X. Sun, Y. Cai, Z. Yang, G. Lei, Y. Guo, and J. Zhu, "Torque analysis and dynamic performance improvement of a PMSM for EVs by skew angle optimization," IEEE Trans. Appl. Supercond., Vol. 29, 1-5, 2019. Google Scholar

16. Lei, G., G. Bramerdorfer, B. Ma, Y. Guo, and J. Zhu, "Robust design optimization of electrical machines: Multi-objective approach," IEEE Trans. Energy Convers., Vol. 36, 390-401, 2021.
doi:10.1109/TEC.2020.3003050 Google Scholar

17. Wang, M., C. Tong, Z. Song, et al. "Performance analysis of an axial magnetic field modulated brushless double rotor machine for hybrid electric vehicles," IEEE Transactions on Industrial Electronics, Vol. 66, No. 4, 806-817, 2019.
doi:10.1109/TIE.2018.2844810 Google Scholar

18. Guo, B., Y. Huang, F. Peng, et al. "Analytical modeling of misalignment in axial flux permanent magnet machine," IEEE Transactions on Industrial Electronics, Vol. 67, No. 6, 4433-4443, 2020.
doi:10.1109/TIE.2019.2924607 Google Scholar

19. Yang, Y. B., X. H. Wang, X. Zhang, et al. "Cogging torque reduction method of magnet shifting in permanent magnet motors," Transactions of China Electrotechnical Society, Vol. 21, No. 10, 22-25, 2006. Google Scholar

20. Huang, Y. K., T. Zhou, J. N. Dong, et al. "A review of axial permanent magnet motors and their research and development," Proceedings of the CSEE, Vol. 35, No. 1, 192-205, 2015. Google Scholar

21. Wu, S. S., B. J. Wang, T. Zhang, and Q. H. Gu, "Design optimization and electromagnetic performance analysis of an axial-flux permanent magnet brushless dc motor with unequal-thickness magnets," Appl. Sci., Vol. 12, No. 15, 7863, 2022.
doi:10.3390/app12157863 Google Scholar

22. Ni, Y. Y., L. Wang, and Q. J. Wang, "Modeling and analysis of convex unequal-thickness pole permanent magnet motor," Journal of Electrotechnology Journal of Electrotechnology, Vol. 35, No. 11, 2406-2414, 2020. Google Scholar

23. Ni, Y. Y., L. Wang, and M. M. Ge, "Analytical modeling and optimization of three-section unequal thickness Halbach permanent magnet motor," Journal of Hefei University of Technology (Natural Science Edition), Vol. 43, No. 3, 349-357, 2020. Google Scholar

24. Li, J. Z., X. Z. Wu, and C. T. Chen, "Analytical calculation of air-gap magnetic field of permanent magnet motor based on magnetic pole segmentation," Chinese Journal of Electrical Engineering, Vol. 41, No. 18, 6390-6399, 2021. Google Scholar

25. Liu, F., T. Deng, and X. B. Hua, "Research on electromagnetic structure design and heat dissipation of disc permanent magnet synchronous motor," Journal of Chongqing University of Technology (Natural Sciences), Vol. 35, No. 12, 77-84, 2021. Google Scholar

26. Hao, L., M. Y. Lin, D. Xu, et al. "Cogging torque reduction in axial field flux-switching permanent magnet machines," Transactions of China Electrotechnical Society, Vol. 30, No. 2, 21-26, 2015. Google Scholar

27. Tao, C. X., M. L. Fu, F. Y. Gao, et al. "Effects of auxiliary slots on the torque of an interior permanent-magnet synchronous motor," Journal of Chongqing University, Vol. 44, No. 4, 64-76, 2021. Google Scholar

28. Zhang, X. C., X. Y. Yang, and J. H. Cao, "Performance analysis of permanent magnet brushless DC motor with unequal thick magnetic poles," Micro Motor, Vol. 42, No. 2, 9-13, 2014. Google Scholar

29. Xu, Y. L., L. J. Xu, and Q. L. Gao, "Size equation and magnetic network model of yoke block armature axial magnetic field permanent magnet motor," Electric Machines and Control, Vol. 23, No. 11, 27-32, 2019. Google Scholar

30. Gong, X. and Y. L. Xu, "Lumped parameter magnetic circuit analysis of axial ux permanent magnet motor and its analytical calculation of air gap leakage," Electric Machines and Control, Vol. 17, No. 10, 59-64, 2013. Google Scholar

31. Xu, L., X. Y. Zhu, C. Zhang, et al. "Torque quality analysis and optimization design of magnetic pole radial combined axial magnetic field permanent magnet motor," Proceedings of the CSEE, Vol. 41, No. 6, 1971-1983, 2021. Google Scholar

32. Xie, Y. and C. M. Qu, "Design and study of disc coreless motor with trapezoidal permanent magnet," Electric Machine and Control, Vol. 20, No. 8, 7482, 2016. Google Scholar

33. Liu, J. Q., J. G. Bai, P. Zheng, G. P. Liu, and J. X. Huang, "Research on cogging torque based on magnetic field modulation principle," Journal of Electrotechnology, Vol. 35, No. 5, 931-941, 2020. Google Scholar

34. Gao, F. Y., X. D. Qi, X. F. Li, et al. "Analytical calculation and optimization analysis of electromagnetic performance of Halbach partial segmented permanent magnet synchronous motor of unequal width and thickness," Transactions of China Electrotechnical Society, Vol. 37, No. 6, 1398-1414, 2022. Google Scholar

Dr. Jianwei Liang

Dr. Xinhua Wang

Dr. Peiyao Guo

Dr. Huan Liu

Dr. Xuchang Yuan

Dr. Dong Chen