This paper presents a technical which improves energy efficiency of AC rotating machines by using Grain Oriented (GO) steel at stator core instead of Non Oriented (NO) steel. The losses of GO steel are less important only if the magnetic flux circulates along the rolling direction; consequently it is rarely used in AC machines where the magnetic flux rotates. By stacking many shifted GO laminations of AC machine stator, the flux pass from one lamination to another, and the core losses are reduced. A lot of experimentations have been done with unidirectional field, rotating field and with real induction machines. They show important improvements with GO shifted steel. The efficiency difference between a classical 10kW induction machine and a modified machine with GO stator is more than 2 points. Moreover, the no-load current and so the reactive power are smaller. This technical creates environmental and financial gains.
2. Hanitsch, R., "Energy efficient electric motors," World, Climate and Energy Event, Rio, 2002.
3., "Rotating electrical machines-efficiency classes of single-speed, three-phase, cage-induction motors,", International Standard IEC 60034-30, 2008.
4. Aoulkadi, M. and A. Binder, "When loads stray: Evaluation of different measurement methods to determine stray load losses in induction machines," IEEE Industrial Electronics Magazine, Vol. 2, No. 1, 21-30, Mar. 2008.
5. Nagornyy, A., A. K. Wallace, and A. V. Jouanne, "Stray load loss efficiency connections," IEEE Industry Applications Magazine, Vol. 10, No. 3, 62-69, 2004.
6. Enokizono, M., T. Todaka, H. Shimoji, and A. Ikariga, "Optimum design of rotating machines using grain-oriented electrical steel sheet by two-dimensional vector magnetic property," nternational Aegean Conference on Electrical Machines and Power Electronics, ACEMP’ 07, 468-473, 2007.
7. Steinmetz, C., "On the law of hysteresis," Proceedings of the IEEE, Vol. 72, 197-221, 1984.
8. Bertotti, G., "General properties of power losses in soft ferromagnetic materials," IEEE Trans. on Magnetics, Vol. 24, No. 1, 621-630, Jan. 1988.
9. Lopez, S., "D´efinition de nouvelles structures de circuits magnetiques de machines a courant alternatif utilisant des toles a grains orientes,", Ph.D. Thesis, Univ. Lille Nord de France, Univ. Artois, LSEE, France, 2011.
10. Hihat, N., K. Komeza, E. Napieralska, and J. P. Lecointe, "Experimental and numerical characterization of magnetically anisotropic laminations in the direction normal to their surface," IEEE Trans. on Magnetics, Vol. 47, No. 11, 4517-452, Oct. 2011.
11. Andrei, H. and F. Spinei, "The minimum energetical principle in electric and magnetic circuits," Proc. 18th ECCTD, Vol. 99, 906-909, 2007.
12. Parent, G., R. Penin, J. P. Lecointe, J. F. Brudny, and T. Belgrand, "Analysis of the magnetic flux distribution in a new shifted non segmented grain oriented AC motor magnetic circuit," IEEE Trans. on Magnetics, Vol. 49, No. 5, 1977-1980, Apr. 2013.
13. Lopez, S., B. Cassoret, J. F. Brudny, L. Lefebvre, and J. N. Vincent, "Grain oriented steel assembly characterization for the development of high efficiency AC rotating electrical machines," IEEE Trans. on Magnetics, Vol. 45, No. 10, 4161-4164, Oct. 2009.
14. Brudny, J. F., B. Cassoret, R. Lemaitre, and J. N. Vincent, "Magnetic core and use of magnetic core for electrical machines,", International Patent PCT/EP2008/061884, Mar. 2009.
15. Findlay, R. D., N. Stranges, and D. K. MacKay, "Losses due to rotational flux in three phase induction motors," IEEE Trans. on Energy Conversion, Vol. 9, No. 3, 543-549, 1994.
16. Lopez, S., L. Lefebvre, B. Cassoret, J. F. Brudny, and J. N. Vincent, "Validation of a high efficiency AC rotating electrical machine magnetic circuit by particular tests at standstill," Proc. Soft Magnetic Materials, Ref. C2-01, Torino, Italy, Sep. 2009.
17. Cao, W., "Comparison of IEEE 112 and new IEC Standard 60034-2-1," IEEE Trans. on Energy Conversion, Vol. 24, No. 3, 802-808, 2009.
18. McKinnon, D. J. and C. Grantham, "Improved efficiency test methods for three-phase induction machines," Industry Applications Conference, Fourtieth IAS Annual Meeting, Conference Record of the 2005, Vol. 1, 466-473, 2005.
19. Boughanmi, W., J. P. Manata, D. Roger, T. Jacq, and F. Streiff, "Life cycle assessment of a three-phase electrical machine in continuous operation," IET Electric Power Applications, Vol. 6, No. 5, 277-285, 2012.
20. Demian, C., B. Cassoret, J. F. Brudny, and T. Belgrand, "AC magnetic circuits using non segmented shifted grain oriented electrical steel sheets: Impact on induction machine magnetic noise," IEEE Trans. on Magnetics, Vol. 48, No. 4, 1409-1412, 2012.
21. Penin, R., J. P. Lecointe, G. Parent, J. F. Brudny, and T. Belgrand, "Estimation of relative magnetostriction and Maxwell’s forces in stacked grain oriented steel structures," Proc. International Conference on Electrical Machines, 1971-1976, Sep. 2012.