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Experimental Validation and Performance Analysis of Flux Switching Permanent Magnet Machines Using the Virtual Current Method for EV/HEV Applications


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Received: 12 November 2025; Revised: 24 December 2025; Accepted: 29 December2025; Published: 8 January 2026
This paper experimentally validates the Virtual Current Method (VCM) for predicting the air-gap magnetic field and performance of a 12/10 Flux Switching Permanent Magnet (FSPM) machine. Unlike prior VCM studies, which are mainly limited to analytical derivation or numerical verification, this work provides a full experimental assessment using a fabricated FSPM prototype. The prototype was designed based on the proposed analytical model, and a dedicated test bench was developed to measure back-electromotive force (EMF), electromagnetic torque, and air-gap flux density under various load conditions. Experimental measurements are systematically compared with both analytical predictions and 2D finite element method (FEM) simulations. Results show that the VCM-based model predicts the air-gap flux density with a maximum deviation of 3.6% from experiments and 2.8% from FEM. The prototype delivers an average torque of 5.4 N·m at 5 A root mean square (RMS) phase current, achieving a power factor of 0.89 and efficiency above 93%. These findings confirm that the proposed VCM formulation provides a reliable, low-computational-cost, and experimentally validated tool suitable for preliminary design and performance optimization of FSPM machines. The study highlights the practical applicability of VCM, bridging the gap between analytical models and experimental performance evaluation in advanced electric machine design.
Keywords:
Flux Switching Permanent Magnet (FSPM) Machine Virtual Current Method (VCM) Experimental Validation Back‑EMF Torque Measurement Finite Element Method (FEM)References
- Zhu, Z.Q.; Howe, D. Electrical machines and drives for electric, hybrid, and fuel cell vehicles. Proc. IEEE 2007, 95, 746–765. DOI: https://doi.org/10.1109/JPROC.2006.892482
- Gobbi, M.; Sattar, A.; Palazzetti, R.; et al. Traction motors for electric vehicles: Maximization of mechanical efficiency—A review. Appl. Energy 2024, 357, 122496. DOI: https://doi.org/10.1016/j.apenergy.2023.122496
- Rimpas, D.; Kaminaris, S.D.; Piromalis, D.D.; et al. Comparative review of motor technologies for electric vehicles powered by a hybrid energy storage system based on multi-criteria analysis. Energies 2023, 16, 2555. DOI: https://doi.org/10.3390/en16062555
- Öner, Y. Analytical model of flux switching permanent magnet machine under armature reaction condition. Int. J. Appl. Electromagn. Mech. 2016, 51, 297–306. DOI: https://doi.org/10.3233/JAE-160020
- Azeem, M.; Kim, B. Electromagnetic analysis and performance investigation of flux-switching permanent magnet machine. Energies 2019, 12, 3362. DOI: https://doi.org/10.3390/en12173362
- Ilhan, E.; Gysen, B.L.J.; Paulides, J.J.H.; et al. Analytical hybrid model for flux switching permanent magnet machines. IEEE Trans. Magn. 2010, 46, 1762–1765. DOI: https://doi.org/10.1109/TMAG.2010.2042579
- Farrokh, F.; Vahedi, A.; Torkaman, H.; et al. A 2D hybrid analytical electromagnetic model of the dual-stator axial-field flux-switching permanent magnet motor. IET Electr. Power Appl. 2023, 18, 252–264. DOI: https://doi.org/10.1049/elp2.12385
- Nobahari, A.; Aliahmadi, M.; Faiz, J. Performance modifications and design aspects of rotating flux-switching permanent magnet machines: A review. IET Electr. Power Appl. 2020, 14, 1–15. DOI: https://doi.org/10.1049/iet-epa.2019.0339
- Krishnan, R. Electric Motor Drives: Modeling, Analysis, and Control; Pearson: Upper Saddle River, NJ, USA, 2020.
- Nategh, S.; Boglietti, A.; Liu, Y.; et al. A review on different aspects of traction motor design for railway applications. IEEE Trans. Ind. Appl. 2020, 56, 2148–2157. DOI: https://doi.org/10.1109/TIA.2020.2968414
- Farrokh, F.; Vahedi, A.; Torkaman, H.; et al. Design and comparison of dual-stator axial-field flux-switching permanent magnet motors for electric vehicle application. IET Electr. Syst. Transp. 2023, 13, e12074. DOI: https://doi.org/10.1049/els2.12074
- Cheng, Y.; Ding, L.; Zhao, T.; et al. Design and optimization of electric vehicle traction motor considering rotor topology and manufacturing uncertainty. IEEE Trans. Ind. Electron. 2024, 71, 5034–5044. DOI: https://doi.org/10.1109/TIE.2023.3288195
- Curti, M.; Paulides, J.J.H.; Lomonova, E.A. An overview of analytical methods for magnetic field computation. In Proceedings of the 10th IEEE International Conference on Ecological Vehicles and Renewable Energies, Monte Carlo, Monaco, 31 March–2 April 2015; pp. 1–7. DOI: https://doi.org/10.1109/EVER.2015.7112938
- Wu,Z.Z.; Zhu, Z.Q. Analysis of air-gap field modulation and magnetic gearing effects in switched flux permanent magnet machines. IEEE Trans. Magn. 2015, 51, 8105012. DOI: https://doi.org/10.1109/TMAG.2015.2402201
- Vahaj, A.A.; Rahideh, A.; Lubin, T. General analytical magnetic model for partitioned-stator flux-reversal machines with four types of magnetization patterns. IEEE Trans. Magn. 2019, 55, 1–21.
- Gieras, J.F. Electrical Machines: Fundamentals of Electromechanical Energy Conversion; CRC Press: Boca Raton, FL, USA, 2020.
- Scuiller, F. Magnetic equivalent circuit modeling of permanent magnet machines: Accuracy versus complexity trade-offs. IEEE Access 2022, 10, 99912–99925.
- Hu, J.; Liu, F.; Li, Y. An improved sub-domain model of flux-switching permanent magnet machines considering harmonic analysis and slot shape. IEEE Access 2021, 9, 55260–55270. DOI: https://doi.org/10.1109/ACCESS.2021.3071792
- Tang, C.; Shen, M.; Fang, Y.; et al. Comparison of Subdomain, Complex Permeance, and Relative Permeance Models for a Wide Family of Permanent-Magnet Machines. IEEE Trans. Magn. 2021, 57, 8101205. DOI: https://doi.org/10.1109/TMAG.2020.3009416
- Shirzad, E.; Rahideh, A. Analytical model for brushless double mechanical port flux-switching permanent magnet machines. IEEE Trans. Magn. 2021, 57, 8107713. DOI: https://doi.org/10.1109/TMAG.2021.3104938
- Wang, X.; Wang, Y.; Wu, T. The review of electromagnetic field modeling methods for permanent-magnet linear motors. Energies 2022, 15, 3595. DOI: https://doi.org/10.3390/en15103595
- Faradonbeh, V.Z.; Rahideh, A.; Markadeh, G.A. Analytical model for slotted stator brushless surface-inset permanent magnet machines using virtual current theory. IET Electr. Power Appl. 2020, 14, 2750–2761.
- Rahideh, A.; Korakianitis, T. Analytical magnetic field calculation of slotted brushless permanent-magnet machines with surface inset magnets. IEEE Trans. Magn. 2012, 48, 2633–2649. DOI: https://doi.org/10.1109/TMAG.2012.2200691
- Jing, L.; Yang, K.; Gao, Y.; et al. Analysis and optimization of a novel flux reversal machine with auxiliary teeth. Energies 2022, 15, 8906. DOI: https://doi.org/10.3390/en15238906
- Abunike, C.E.; Dowlatshahi, M.; Jamshidi Far, A.; et al. Multi-objective optimization of a flux-switching wound-field machine using a response surface-based multi-level design approach. Results Eng. 2025, 25, 103988. DOI: https://doi.org/10.1016/j.rineng.2025.103988
- Chen, M.; Huang, L.; Li, Y.; et al. Analysis of magnetic gearing effect in field-modulated transverse flux linear generator for direct drive wave energy conversion. IEEE Trans. Magn. 2021, 58, 8101905. DOI: https://doi.org/10.1109/TMAG.2021.3081799
- Krings, A.; Monissen, C. Review and trends in electric traction motors for battery electric and hybrid vehicles. In Proceedings of the 2020 International Conference on Electrical Machines (ICEM), Gothenburg, Sweden, 23–26 August 2020; pp. 1807–1813. DOI: https://doi.org/10.1109/ICEM49940.2020.9270946
- He, T.; Zhu, Z.; Eastham, F.; et al. Permanent magnet machines for high-speed applications. World Electr. Veh. J. 2022, 13, 18. DOI: https://doi.org/10.3390/wevj13010018
- Shirzad, E. Substitution Analytical Model for Finite Element Method to Predict Distribution of Flux density for Flux Switching Permanent Magnet with E-Core Shape of Stator at no load. J. Phys. Astron. 2024, 12, 379.
- Zhou, Y.; Wu, X. Analytical calculation of magnetic field of bearingless flux-switching permanent-magnet machine based on doubly-salient relative permeance method. IET Electr. Power Appl. 2020, 5, 872–884. DOI: https://doi.org/10.1049/iet-epa.2019.0522
- Zhu, Z.Q.; Howe, D.; Chan, C.C. Improved analytical model for predicting the magnetic field distribution in brushless permanent-magnet machines. IEEE Trans. Magn. 2002, 38, 229–238. DOI: https://doi.org/10.1109/20.990112
- Shirzad, E. Distinction direction of flux for PMs used to analyze slotless linear motors with buried PMs considering finite iron core for HEVs usages. Int. J. Invent. Eng. Sci. 2025, 12, 20–28. DOI: https://doi.org/10.35940/ijies.C8290.12101025

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