This paper presents a novel permanent-magnet (PM) machine for wind power generation. In order to achieve high power/torque density as well as get rid of the nuisances aroused by the mechanical gearbox, a coaxial magnetic gear (CMG) is engaged. Different from the existing integrated machine in which armature windings are deployed in the inner bore of the CMG as an individual part, stator windings are directly inserted among the slots between the ferromagnetic segments in this proposed machine. Thus, it can offer several merits, such as simpler mechanical structure, better utilization of PM materials and lower manufacturing cost. Moreover, by artfully designing the connection of the armature windings, the electromagnetic coupling between the windings and the outer rotor PMs can be dramatically decreased, and the electromechanical energy conversion can be achieved by the field interaction between the inner rotor PMs and the armature windings. This machine adopts an outer-rotor topology, for compact design, the wind blades are directly mounted on the outer rotor of the machine, while the fairing is equipped on the front end of the stator. The design details and operating principle are elaborated. By using the time-stepping finite element method (TSFEM), the electromagnetic characteristics of the proposed machine are analyzed. The results verify the validity of the proposed machine.
2. Grauers, A., "Efficiency of three wind energy generator systems," IEEE Trans. Energy Conversion, Vol. 11, No. 3, 650-657, 1996.
3. Muller, S., "Doubly fed induction generator system for wind turbines," IEEE Ind. Appl. Magazine, Vol. 8, No. 3, 26-33, 2002.
4. Torrey, D., "Switched reluctance generators and their control," IEEE Trans. Ind. Electron., Vol. 49, No. 1, 3-13, 2002.
5. Fan, Y., K. T. Chau, and M. Cheng, "A new three-phase doubly salient permanent magnet machine for wind power generation," IEEE Trans. Ind. Appl. Magazine, Vol. 42, No. 1, 53-59, 2006.
6. Chau, K. T., Y. Li, J. Jiang, and S. Niu, "Design and control of a PM brushless hybrid generator for wind power application," IEEE Trans. Magn., Vol. 42, No. 10, 3497-3499, 2006.
7. Niu, S., K. T. Chau, J. Jiang, and C. Liu, "Design and control of a new double-stator cup-rotor permanent-magnet machine for wind power generation," IEEE Trans. Magn., Vol. 43, No. 6, 2501-2503, 2007.
8. Chen, J., C. V. Nayar, and L. Xu, "Design and finite-element analysis of an outer-rotor permanent magnet generator for directly coupled wind turbines," IEEE Trans. Magn., Vol. 36, No. 5, 3802-3809, 2000.
9. Atallah, K., S. Calverley, and D. Howe, "Design, analysis and realization of a high-performance magnetic gear," IEE Proc. Electric Power Appl., Vol. 151, No. 2, 135-143, 2004.
10. Jian, L. and K.-T. Chau, "Analytical calculation of magnetic field distribution in coaxial magnetic gears," Progress In Eletromagnetics Research, Vol. 92, 1-16, 2009.
11. Jian, L. and K. T. Chau, "A coaxial magnetic gear with halbach permanent-magnet arrays," IEEE Trans. Energy Conversion, Vol. 25, No. 2, 319-328, 2010.
12. Jian, L., K. T. Chau, W. Li, and J. Li, "A novel coaxial magnetic gear using bulk HTS for industrial applications," IEEE Trans. Appl. Superconduc., Vol. 20, No. 3, 981-984, 2010.
13. Chau, K. T., D. Zhang, J. Jiang, C. Liu, and Y. Zhang, "Design of a magnetic-geared outer-rotor permanent-magnetic brushless motor for electric vehicles," IEEE Trans. Magn., Vol. 43, No. 6, 2504-2506, 2007.
14. Jian, L. and K.-T. Chau, "Design and analysis of a magnetic-geared electronic-continuously variable transmission system using finite element method," Progress In Eletromagnetics Research, Vol. 107, 47-61, 2010.
15. Jian, L., K. T. Chau, and J. Jiang, "A magnetic-geared outer-rotor permanent-magnet brushless machine for wind power generation," IEEE Trans. Ind. Appl., Vol. 45, No. 3, 954-962, 2009.
16. Faiz, J. and B. M. Ebrahimi, "Mixed fault diagnosis in three-phase squirrel-cage induction motor using analysis of air-gap magnetic field," Progress In Eletromagnetics Research, Vol. 64, 239-255, 2006.
17. Vaseghi, B., N. Takorabet, and F. Meibody-Tabar, "Transient finite element analysis of induction machines with stator winding turn fault," Progress In Eletromagnetics Research, Vol. 95, 1-18, 2009.
18. Faiz, J., B. M. Ebrahimi, and M. B. B. Sharifian, "Time stepping finite element analysis of broken bars fault in a three-phase squirrel-cage induction motor," Progress In Eletromagnetics Research, Vol. 68, 53-70, 2007.
19. Chari, M. V. K., G. Bedrosian, J. D'Angelo, A. Konrad, G. M. Cotzas, and M. R. Shah, "Electromagnetic field analysis for electrical machine design," Progress In Eletromagnetics Research, Vol. 04, 159-211, 1991.
20. Touati, S., R. Ibtiouen, O. Touhami, and A. Djerdir, "Experimental investigation and optimization of permanent magnet motor based on coupling boundary element method with permeances network," Progress In Eletromagnetics Research, Vol. 111, 71-90, 2011.
21. Lecointe, J.-P., B. Cassoret, and J. F. Brudny, "Distinction of toothing and saturation effects on magnetic noise of induction motors," Progress In Eletromagnetics Research, Vol. 112, 125-137, 2011.
22. Ravaud, R. and G. Lemarquand, "Comparsion of the coulombian and amperian current models for calculating the magnetic field produced by radially magnetized arc-shaped permanent magnets," Progress In Eletromagnetics Research, Vol. 95, 309-327, 2009.
23. Tian, J., Z.-Q. Lv, X.-W. Shi, L. Xu, and F. Wei, "An efficient approach for multiforntal algorithm to solve non-positive-definite finite element equations in electromagnetic problems," Progress In Eletromagnetics Research, Vol. 95, 121-133, 2009.
24. Ping, X. W. and T.-J. Cui, "The factorized sparse approximate inverse preconditioned conjugate gradient algorithm for finite element analysis of scatering problems," Progress In Eletromagnetics Research, Vol. 98, 15-31, 2009.
25. Chen, J. and Q. H. Liu, "A non-spurious vector spectral element method for maxwell's equations," Progress In Eletromagnetics Research, Vol. 96, 205-215, 2009.
26. Chau, Y.-F., H.-H. Yeh, and D. P. Tsai, "A new type of optical antenna: plasmonics nanoshell bowtie antenna with dielectric hole," Journal of Electromagnetic Waves and Applications, Vol. 24, No. 11-12, 1621-1632, 2010.
27. Khalilpour, J. and M. Hakkak, "Controllable waveguide bandstop filter using S-shaped ring resonators," Journal of Electromagnetic Waves and Applications, Vol. 24, No. 5-6, 587-596, 2010.