F. N. U. Nishanth, J. Van Verdeghem and E. L. Severson, “Recent advances in analysis and design of axial flux permanent magnet electric machines,” IEEE Energy Conversion Congress and Exposition, ECCE, pp. 3745-3752, 2021. DOI:10.1109/ECCE47101.2021.9595085

Z. Zhang, C. Wang and W. Geng, “Design and optimization of Halbach-array PM rotor for high-speed axial-flux permanent magnet machine with ironless stator,” IEEE Transactions on Industrial Electronics, vol. 67, no. 9, pp. 7269-7279, 2019. DOI:10.1109/TIE.2019.2944033

Y. Lu, Y. Kai, S. Songjun, Y. Lixiao, X. Fei and L. Cheng, “Study on the influence of a combined-Halbach array for the axial flux permanent magnet electrical machine with yokeless and segmented armature,” IEEE Transactions on Magnetics, vol. 60, no. 3, pp. 1-5, 2023. DOI:10.1109/TMAG.2023.3287708

M. Aydin and M. Gulec, “Reduction of cogging torque in double-rotor axial-flux permanent-magnet disk motors: A review of cost-effective magnet-skewing techniques with experimental verification,” IEEE Transactions on Industrial Electronics, vol. 61, no. 9, pp. 5025-5034, 2013. DOI:10.1109/TIE.2013.2276777

A. B. Letelier, D. A. Gonzalez, J. A. Tapia, R. Wallace and M. A. Valenzuela, “Cogging torque reduction in an axial flux PM machine via stator slot displacement and skewing,” IEEE Transactions on Industry Applications, vol. 43, no. 3, pp. 685-693, 2007. DOI:10.1109/TIA.2007.895738

C. K. Kim, S. G. Lee and S. Y. Jung, “Design of cogging torque and torque ripples reduction for high precision controlled SPMSM,” The Transactions of the Korean Institute of Electrical Engineers, vol. 58, no. 10, pp. 1923-1929, 2010.

W. Geng and Z. Zhang, “Analysis and implementation of new ironless stator axial-flux permanent magnet machine with concentrated nonoverlapping windings,” IEEE Transactions on Energy Conversion, vol. 33, no. 3, pp. 1274-284, 2018. DOI:10.1109/TEC.2018.2799172

Z. Zhang, C. Wang and W. Geng, “Design and Optimization of Halbach-Array PM Rotor for High-Speed Axial-Flux Permanent Magnet Machine With Ironless Stator,” IEEE Transactions on Industrial Electronics, vol. 67, no. 9, pp. 7269-7279, 2019. DOI:10.1109/TIE.2019.2944033