In this paper, two variable leakage flux permanent magnet (VLFPM) machines are proposed. The keys are to adopt the rotor with single-layer and double-layer PMs and intentionally create leakage flux paths to extend the operating speed range and increase the machine efficiency. The characteristics of the variable leakage flux of the proposed machines are investigated. In order to improve the performances of the VLFPM machines, the Multi-Objective Genetic Algorithm (MOGA) method is applied for achieving the multi-objective optimizations of variables. Then, the performances of the double-layer permanent magnet variable leakage flux motor (DLPM-VLFM) and the single-layer permanent magnet variable leakage flux motor (SLPM-VLFM) are analyzed and compared with conventional interior PM machine (CIPMM) in detail. The performances mainly include flux linkage and torque, flux-weakening capability and efficiency. Finally, it is shown by analysis and comparison that the DLPM-VLFM can have a wider range of speed and high efficiency.
2. Kakosimos, P. E., A. G. Sarigiannidis, M. E. Beniakar, A. G. Kladas, and C. Gerada, "Induction motors versus permanent-magnet actuators for aerospace applications," IEEE Transactions on Industrial Electronics, Vol. 61, No. 8, 4315-4325, 2014.
3. Yang, Y. Y., S. M. Castano, R. Yang, M. Kasprzak, B. Bilgin, A. Sathyan, H. Dadkhah, and A. Emadi, "Design and comparison of interior permanent magnet motor topologies for traction applications," IEEE Transactions on Transportation Electrification, Vol. 3, No. 1, 86-97, 2017.
4. Yang, Z., F. Shang, I. P. Brown, and M. Krishnamurthy, "Comparative study of interior permanent magnet, induction, and switched reluctance motor drives for EV and HEV applications," IEEE Transactions on Transportation Electrification, Vol. 1, No. 3, 245-254, 2015.
5. Jang, J., M. Humza, and B. Kim, "Design of a variable-flux permanent-magnet synchronous motor for adjustable-speed operation," IEEE Transactions on Industry Applications, Vol. 52, No. 4, 2996-3004, 2016.
6. Kim, K.-C., "A novel magnetic flux weakening method of permanent magnet synchronous motor for electric vehicles," IEEE Transactions on Magnetics, Vol. 48, No. 11, 4042-4045, 2012.
7. Kohara, A., K. Hirata, N. Niguchi, and Y. Ohno, "Finite-element analysis and experiment of current superimposition variable flux machine using permanent magnet," IEEE Transactions on Magnetics, Vol. 52, No. 9, 18-25, 2016.
8. Kato, T., N. Limsuwan, C. Y. Yu, K. Akatsu, and R. D. Lorenz, "Rare earth reduction using a novel variable magnetomotive force flux-intensified IPM machine," IEEE Transactions on Industry Applications, Vol. 50, No. 3, 1748-1756, 2014.
9. Limsuwan, N., Y. Shibukawa, D. D. Reigosa, and R. D. Lorenz, "Novel design of flux-intensifying interior permanent magnet synchronous machine suitable for self-sensing control at very low speed and power conversion," IEEE Transactions on Industry Applications, Vol. 47, No. 5, 2004-2012, 2011.
10. Zhu, X. Y., W. Y. Wu, S. Yang, Z. X. Xiang, and L. Quan, "Comparative Design and analysis of new type of flux-intensifying interior permanent magnet motors with different q-axis rotor flux barriers," IEEE Transactions on Energy Conversion, Vol. 33, No. 4, 2260-2269, 2018.
11. Hua, H., Z. Q. Zhu, A. Pride, R. Deodhar, and T. Sasaki, "Comparative study on variable flux memory machines with parallel or series hybrid magnets," IEEE Transactions on Industry Applications, Vol. 55, No. 2, 1408-1419, 2019.
12. Hua, H., Z. Q. Zhu, A. Pride, R. P. Deodhar, T. Sasaki, and , "A novel variable flux memory machine with series hybrid magnets," IEEE Transactions on Industry Applications, Vol. 53, No. 5, 4396-4405, 2017.
13. Liu, F. L., L. M. Cheng, M. Q. Wang, G. Y. Qiao, P. Zheng, and H. Yang, "Comparative study of hybrid-PM variable-flux machines with different series PM configurations," AIP Advances, Vol. 9, No. 12, 321-332, 2019.
14. Elloumi, N., M. Bortolozzi, A. Masmoudi, M. Mezzarobba, M. Olivo, and A. Tessarolo, "Numerical and analytical approaches to the modeling of a spoke type IPM machine with enhanced flux weakening capability," IEEE Transactions on Industry Applications, Vol. 55, No. 5, 4702-4714, 2019.
15. Liu, X., T. Sun, Y. Zou, C. Huang, and J. Liang, "Modelling and analysis of a novel mechanical-variable-flux IPM machine with rotatable magnetic poles," IET Electric Power Applications, Vol. 14, No. 11, 2171-2178, 2020.
16. Tessarolo, A., M. Mezzarobba, and R. Menis, "Modeling, analysis, and testing of a novel spoke-type interior permanent magnet motor with improved flux weakening capability," IEEE Transactions on Magnetics, Vol. 51, No. 4, 1-10, 2015.
17. Aoyama, M. and T. Noguchi, "Study and experimental performance evaluation of flux intensifying PM motor with variable leakage magnetic flux," Electrical Engineering In Japan, Vol. 207, No. 4, 36-54, 2019.
18. Kato, T., M. Minowa, H. Hijikata, K. Akatsu, and R. D. Lorenz, "Design methodology for variable leakage flux IPM for automobile traction drives," IEEE Transactions on Industry Applications, Vol. 51, No. 5, 3811-3821, 2015.
19. Kusase, S. and K. Kurihara, "A proposal for a new variable leakage flux motor with interpolar gap and permanent magnets," IEEJ Journal of Industry Applications, Vol. 6, No. 6, 381-386, 2017.
20. Wang, A., Y. Jia, and W. L. Soong, "Comparison of five topologies for an interior permanent-magnet machine for a hybrid electric vehicle," IEEE Transactions on Magnetics, Vol. 47, No. 10, 3606-3609, 2011.
21. Ma, Y., T. W. Ching, W. N. Fu, and S. Niu, "Multi-objective optimization of a direct-drive dual-structure permanent magnet machine," IEEE Transactions on Magnetics, Vol. 55, No. 10, 1-4, 2019.
22. Asef, P., R. B. Perpina, M. R. Barzegaran, A. Lapthorn, and D. Mewes, "Multiobjective design optimization using dual-level response surface methodology and Booth’s Algorithm for permanent magnet synchronous generators," IEEE Transactions on Energy Conversion, Vol. 33, No. 2, 652-659, 2018.
23. Nakata, T., M. Sanada, S. Morimoto, and Y. Inoue, "Automatic design of IPMSMs using a genetic algorithm combined with the coarse-mesh FEM for enlarging the high-efficiency operation area," IEEE Transactions on Industrial Electronics, Vol. 64, No. 12, 9721-9728, 2017.