A1 Refereed original research article in a scientific journal
Investigation of Bearingless Partitioned-Stator Flux-Switching Permanent-Magnet Slice Motors; 
Authors: Madanzadeh, Sadjad; Gruber, Wolfgang; Mallinger, Stefan; Jastrzebski, Rafal P.; Nevaranta, Niko
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Publication year: 2026
Journal: IEEE Access
Volume: 14
First page : 74721
Last page: 74735
eISSN: 2169-3536
DOI: https://doi.org/10.1109/ACCESS.2026.3693609
Publication's open availability at the time of reporting: Open Access
Publication channel's open availability : Open Access publication channel
Web address : https://doi.org/10.1109/access.2026.3693609
Self-archived copy’s web address: https://research.utu.fi/converis/portal/detail/Publication/523587279
Self-archived copy's licence: CC BY
Self-archived copy's version: Publisher`s PDF
Flux-switching permanent-magnet machines have gained popularity because their distinctive design places both the permanent magnets and the windings in the stator. This configuration not only improves the structural integrity of the rotor under centrifugal stresses but also makes cooling of the stationary permanent magnets easier and more efficient compared to rotor permanent-magnet structures. These machines are highly versatile and well-suited for applications requiring bearingless motors, including cleanrooms, medical equipment, and pharmaceutical production. However, because the magnetic core must accommodate both the windings and the permanent magnets, it experiences saturation, resulting in performance constraints. This paper proposes a novel bearingless partitioned-stator flux-switching permanent-magnet slice motor architecture. To support this concept, the study focuses on unaddressed challenges in the electromagnetic design of bearingless slice motors, particularly those related to core saturation and the optimization of torque and force performance. By separating the stator into sections containing permanent magnets and copper, iron core saturation is mitigated, resulting in improved torque density. Machine performance is further improved through winding optimization, where various winding schemes are evaluated. The proposed design and underlying principles are validated using 2D and 3D finiteelement analyses of the optimized configurations. Experimental validation confirms the theoretical findings, providing a thorough understanding of the operational characteristics of the motor.
Keywords:
bearingless motor, double stator, electromagnetic torque, Flux-switching permanent-magnet motor, magnetic levitation, partitioned stator, self-bearing, suspension force
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Funding information in the publication:
This work was supported in part by Business Finland under Grant 1803/31/2022; in part by the Linz Center of Mechatronics GmbH (LCM) within the K2 Center for Symbiotic Mechatronics in the framework of the Austrian Competence Centers for Excellent Technologies (COMET) Program; in part by Tohtoristipendi 2021 Säätö ja digitaali; in part by the Academy of Finland under Grant 350880; and in part by the Centre of Excellence in High-Speed Energy Conversion Systems funded by the Research Council of Finland (RCF).
