Keywords
torque
eddy current losses
slotted design
slotless design двигун з постійними магнітами
крутний момент
втрати на вихрові струми
пазова конструкція
безпазова конструкція
How to Cite
Abstract
The advantages and disadvantages of two permanent magnet motor designs – slotted and slotless – are analyzed. A commercially available micromotor was adopted as the slotted design. Their performance is compared in terms of torque production and permanent magnet heating under intensive operating conditions. The rotor geometry was assumed to be identical, the maximum flux density in the magnetic cores was set to 1,7 T, and the rotational speed was considered constant. Modeling was carried out using COMSOL Multiphysics, with the results for the slotted design validated using the Simcenter Motorsolve software package. The torque and the amplitude of torque pulsations for both designs were evaluated, and the differences between them were analyzed. The causes of magnetic flux density pulsations in the magnets were studied, and their impact on eddy current losses was assessed. Numerical results for the output parameter ratios of the two designs were presented. The possibility of neglecting magnet heating in the slotless design was emphasized. References 11, figures 8, table 1.
References
1. Islam M. S., Husain I., Mikail R. Slotless Lightweight Motor for Drone Applications. IEEE Energy Conversion Congress and Exposition (ECCE), Cincinnati, OH, 01-05 October 2017. DOI: https://doi.org/10.1109/ECCE.2017.8096851.
2. Lee Y.-S., Jang I.-S., Yang I.-J., Kim K.-S., Kim W.-H. Study on the Slotless PM Motor Design Proc-ess Considering High Speed. IEEE Trans. Magn. 2024. Vol 60. No 9. Pp. 1–4. DOI: https://doi.org/10.1109/TMAG.2024.3427729.
3. Chattopadhyay R., Islam M. S., Mikail R., Husain I. Slotless Motor with Active Metal Brazed Copper Winding for High Power Density Applications. 2022 IEEE Energy Conversion Congress and Exposition (ECCE), De-troit, MI, USA, 09-13 October 2022. Pp.1–7. DOI: https://doi.org/10.1109/ECCE50734.2022.9948146.
4. Petukhov I.S., Kireyev V.G., Akinin K.P., Lavrinenko V.A. Decreasing torque ripple of a slotless permanent magnet torque motor using a double-layer winding. Tekhnichna Elektrodynamika. 2024. No 4. Pp. 57–62. DOI: https://doi.org/10.15407/techned2024.04.057.
5. Celera Motion. Slotted vs Slotless Motors. URL: https://www.celeramotion.com/frameless-motors/support/technical-papers/slotless-vs-slotted-motors/ (accessed at 2025-06-14).
6. Nisarg Dave, Gaurang Vakil, Zeyuan Xu, Chris Gerada, He Zhang, David Gerada. Comparison of slotted and slotless PM machines for high kW/kg aerospace applications. 23rd International Conference on Electrical Machines and Systems (ICEMS), Hamamatsu, Japan, 24-27 November 2020. DOI: https://doi.org/10.23919/ICEMS50442.2020.9291221.
7. Min S.G., Sarlioglu B. Advantages and Characteristic Analysis of Slotless Rotary PM Machines in Comparison With Conventional Laminated Design Using Statistical Technique. IEEE Trans. Transp. Electrification. 2018. Vol 4. No 2. Pp. 517–524. DOI: https://doi.org/10.1109/TTE.2018.2810230.
8. Scorpion Power System. Scorpion SII-4020-630KV. URL: https://www.scorpionsystem.com/catalog/aeroplane/motors_1/sii-40/SII_4020-630/ (accessed at 2025-07-26).
9. Antonov A.E. Electric machines of magnetoelectric type. Fundamentals of Theory and Synthesis. Kyiv: Institute of Electrodynamics National Academy of Sciences of Ukraine, 2011. 216 p. (Rus)
10. COMSOL: Multiphysics Software for Optimizing Designs. COMSOL. URL: https://www.comsol.com/ (accessed at 2025-07-08).
11. Siemens. What’s New in Simcenter Motorsolve and Simcenter SPEED 2021.1? URL: https://blogs.sw.siemens.com/simcenter/whats-new-in-simcenter-motorsolve-and-simcenter-speed-2021-1/ (accessed 2025-07-26).
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