Document Type : Research Paper

Authors

1 Mechanical, Faculty of technology, EL-OUED University - ALGERIA.

2 Mechanical Engineering Dept., KHENCHELA University, ALGERIA.

3 Mechanical Engineering Dept., Faculty of Technology, University of EL-Oued, 39000 EL-Oued, ALgeria.

Abstract

This paper presents the simulation results of the thermal behavior for an externally cooled asynchronous electric motor in both steady and transient states cases. For this purpose, a mathematical model based on the heat equation is first developed to determine internal thermal sources such as copper, mechanical and iron losses. Then, a computer program is developed to numerically simulate the proposed mathematical model. This program determines the radial distribution of steady and transient states temperatures, and predicts the effect of the ambient temperature on the transient and permanent temperature distributions. This makes it possible to calculate the specific speed of the motor as a function of its rotation speed, the airflow rate and the pressure dropping at the fan level. The obtained results show that the engine heating is mainly due to the elements that show thermal losses by Joule effect. The mitigation of these losses is strictly related with the specific speed, which makes it possible to select the right choice of the engine cooling system. Using the nodal numerical method to determine the distribution of the radial temperature in both steady and transient states cases under the effect of the ambient temperature. The obtained results are analyzed and discussed.

Graphical Abstract

Highlights

  • A mathematical model is developed to determine the internal thermal sources .
  • A computer program is developed to numerically simulate the proposed model.
  • The mitigation of thermal losses is strictly related to the specific speed. 

Keywords

[1] T. I. Kang, C. O. Ahn, I. S. Seo, and S. H. Lee, Numerical analysis for prediction of flow rate of the motor cooling fan, Journal of mechanical science and technology, 22 (2008) 1870-1875, UCI : G704-000058.2008.22.10.001  .
[2] S. Moon and S. Lee, High-Reliable Temperature Prediction Considering Stray Load Loss for Large Induction Machine, IEEE Transactions on Magnetics, 55 (2019) 1-5,doi: 10.1109/TMAG.2019.2901862.
[3] Y. Gai, M. Kimiabeigi, Y. C. Chong, J. D. Widmer, X. Deng, M. Popescu, et al., Cooling of Automotive Traction Motors: Schemes, Examples, and Computation Methods, IEEE Transactions on Industrial Electronics, 66 (2018) 1681-1692,  doi: 10.1109/TIE.2018.2835397.
[4] A. Boglietti, M. Cossale, M. Popescu, and D. A. Staton, Electrical Machines Thermal Model: Advanced Calibration Techniques, IEEE Transactions on Industry Applications, 55( 2019) 2620-2628, doi: 10.1109/TIA.2019.2897264.
[5] M. Grabowski, K. Urbaniec, J. Wernik, and K. J. Wołosz, "Numerical simulation and experimental verification of heat transfer from a finned housing of an electric motor," Energy conversion and management, 125 (2016) 91-96, doi.org/10.1016/j.enconman.2016.05.038.
[6] V. Satiraman and R. Saxena, Steady state thermal analysis of electrical machines by EF method, J. Jnsr. Eng.(JNDJA) Elect. Eng. Div,  64 (1984) 201-206.
[7] M. Popescu, D. Staton, A. Boglietti, A. Cavagnino, D. Hawkins, and J. Goss, Modern heat extraction systems for electrical machines-A review, in 2015 IEEE Workshop on Electrical Machines Design, Control and Diagnosis (WEMDCD),   289-296,2015. doi: 10.1109/WEMDCD.2015.7194542.
[8] D. Staton, A. Boglietti, and A. Cavagnino, Solving the more difficult aspects of electric motor thermal analysis, in IEEE International Electric Machines and Drives Conference, 2003. IEMDC''''''''03., 747-755,2003 doi: 10.1109/TEC.2005.847979.
[9] V. Sreenivasan and D. Sengupta, THERMAL DESIGN OF TOTALLY ENCLOSED FAN COOLED INDUCTION-MOTORS,i n IEEE TRANSACTIONS ON POWER APPARATUS AND SYSTEMS, (1977) 1072-1072.
[10] P. Dokopoulos and J. Xypteras, Analysis of transient temperature distribution in a rotating machine, in Int. Conf. on Electrical machines Sept,  5-9 , 1982.
[11] D. Staton, D. Hawkins, and M. Popescu, Thermal Behaviour of Electrical Motors–An Analytical Approach, in INDUCTICA Technical Conference Program, CWIEME, Berlin, 5-7 , 2009.
[12] Z. Tan, X.-g. Song, B. Ji, Z. Liu, J.-e. Ma, and W.-p. Cao, 3D thermal analysis of a permanent magnet motor with cooling fans, in China''''''''s High-Speed Rail Technology, ed: Springer,  577-587 , 2018. doi.org/10.1631/jzus.A1400293 .
[13] K. Sim, Y.-B. Lee, S.-M. Jang, and T. H. Kim, Thermal analysis of high-speed permanent magnet motor with cooling flows supported on gas foil bearings: part I-coupled thermal and loss modeling, Journal of Mechanical Science and Technology,  29 (2015) 5469-5476,  doi: 10.1007/s12206-015-1148-0.
[14] B. Melka, J. Smolka, J. Hetmanczyk, and P. Lasek, Numerical and experimental analysis of heat dissipation intensification from electric motor,Energy, 2019, doi.org/10.1016/j.energy.2019.06.023.
[15] G. Kramer, G. Szepesi, and Z. Siménfalvi, Novel hot air engine and its mathematical model–experimental measurements and numerical analysis, Pollack Periodica,  14 (2019) 47-58,  doi.org/10.1556/606.2019.14.1.5.
[16] J. Nonneman, B. Van der Sijpe, I. T''''''''Jollyn, S. Vanhee, J. Druant, and M. De Paepe, Evaluation of High Performance Rotor Cooling Techniques for Permanent Magnet Electric Motors, in 2021 IEEE International Electric Machines & Drives Conference (IEMDC),  1-7, 2021. doi: 10.1109/IEMDC47953.2021.9449603 .
[17] Y. Sun, S. Zhang, G. Chen, Y. Tang, and F. Liang, Experimental and numerical investigation on a novel heat pipe based cooling strategy for permanent magnet synchronous motors, Applied Thermal Engineering,  170 (2020) 114970. doi.org/10.1016/j.applthermaleng.2020.114970.
[18] E. Gundabattini, R. Kuppan, D. G. Solomon, A. Kalam, D. Kothari, and R. A. Bakar, A review on methods of finding losses and cooling methods to increase efficiency of electric machines, Ain Shams Engineering Journal,  12 (2021) 497-505. doi.org/10.1016/j.asej.2020.08.014 .
[19] Q. Chen and X. Yang, Calculation analysis of thermal loss and temperature field of in-wheel motor in micro-electric vehicle, Journal of Mechanical Science and Technology,  28 (2014) 3189-3195.
[20] R. Glises, G. Hostache, and J. Kauffmann, Simulation du comportement thermique en régime permanent d''''''''un moteur asynchrone à refroidissement extérieur. Etude par éléments finis, Journal de Physique III,  4 (1994) 1723-1735.
[21] D. Roye and R. Perret, Définitions des règles de modélisation thermique des machines électriques tournantes, Revue de physique appliquée, 20 (1985) 191-202.
[22] N. Burais, Etude et modelisation des Pertes dans les circuits magnetiques en Regime Non Sinusoidal a Frequence Industrielle Elevee,1981.
[23] J. Chatelain, Machines électriques vol. 10: PPUR Presses polytechniques, 1989.
[24] F. P. Incropera, A. S. Lavine, T. L. Bergman, and D. P. DeWitt, Fundamentals of heat and mass transfer: Wiley, 2007.
[25] H. G. Johnson, Electric fan motor, ed: Google Patents, 1997.
[26] R. Glises, A. Miraoui, and J. Kauffmann, Thermal modelling for an induction motor, Journal de physique III, 3 (1993) 1849-1859,  doi: 10.1051/jp3:1993245.
[27] M. Bouheraoua, Contribution à la modélisation thermique d''''''''un moteur asynchrone à cage, Université Mouloud Mammeri, 2008.
[28] R. Khaldi, Etude expérimentale du comportement thermique du moteur asynchrone alimenté par convertisseur, 1996.
[29] H. Cortès and J. Blot, Transferts thermiques application à l''''''''habitat: étude par la méthode nodale: Ellipses/ed. marketing SA, 1999.
[30] H. Fraudet, Cours d''''''''électricité tome 1.
R. Glises de la Rivière, Etude théorique et expérimentale des flux thermiques dans un moteur asynchrone à refroidissement extérieur, Besançon, 1994.