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This paper presents the optimal study of a vernier-type axial-flux permanent-magnet (AFPM) machine, which has a high-polarity spoke-type PM rotor, a wound stator with a low number of coils, and a profiled stator. Both stators have profiled teeth to enhance the magnetic interaction between the rotor PM array and stator windings for torque production. Compared to the topology with two wound stators, the studied one has a smaller total axial length and is expected more suitable for applications where the space is limited in axial direction. Both topologies are optimized through 3-dimensional (3D) finite element analysis (FEA) by the combined design of experiments (DOE) based sensitivity analysis and surrogate-assisted multiobjective differential evolution (DE) algorithm. Key factors affecting the two objectives, i.e., total active material cost and total electromagnetic loss, are identified. The optimization results are presented and compared, providing practical guidelines for the optimal design and operation of such machines. The manufacturing aspects and their impacts on the electromagneticperformance are also discussed.
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This content will become publicly available on January 1, 2026
A Review of Segmented Stator and Rotor Designs in AC Electric Machines: Opportunities and Challenges
The use of segmented stator and rotor designs in AC electric machine construction offers several significant advantages, including a high-copper fill factor, increased torque density, improved field-weakening performance, simplified manufacturing processes, and enhanced mechanical strength. Additionally, segmented designs allow for the incorporation of oriented steel—either partially or fully—which exhibits excellent magnetic properties in the rolling direction, resulting in more efficient machine performance. However, lamination segmentation also introduces challenges. Parasitic air gaps between segments and an increased number of cut edges in the assembled stack can alter the magnetic properties of the machine, potentially leading to degraded performance. Furthermore, the use of oriented steel remains complex, as its highly nonlinear magnetic properties vary depending on the direction of the magnetic flux. This paper reviews the widely adopted stator and rotor segmentation techniques available in the literature, discussing their potential benefits and limitations. It also covers key aspects such as popular manufacturing approaches, the impact of segmentation on machine performance, advanced finite-element analysis (FEA) techniques for numerical modeling, and experimental methods for evaluating the performance of segmented stator and rotor constructions in AC machines. By addressing these areas, this work provides a comprehensive resource for machine designers seeking to develop AC machines with segmented stators and rotors.
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- Award ID(s):
- 2045776
- PAR ID:
- 10567431
- Publisher / Repository:
- MDPI
- Date Published:
- Journal Name:
- Eng
- Volume:
- 6
- Issue:
- 1
- ISSN:
- 2673-4117
- Page Range / eLocation ID:
- 7
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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