The aim of this paper is to apply a mathematical model using a lumped parameter thermal method and to conduct experiment test to determine he temperature distribution inside the induction motor to evaluate the thermal stability of the induction motor and to check whether the sulation of the copper windings is sufficient at different operating conditions, and to find out the hottest element which has the main effect on the peration and performance of the motor. We found out from the thermal model analysis that the hottest element in the induction motor is the end winding and rotor bars, this is due to stator copper losses and rotor bars losses which depend on the stator current, the stator current can be increased by increasing the torque or by decreasing the stator frequency, which makes the temperature of each element to increase. The thermal model of the induction motor is validated by comparing the calculated temperatures of each element in the induction motor with the experimental results that obtained from through thermocouples connected to the computer via data logger, and the results showed that the accuracy of the proposed thermal model has uncertainities of about 4% ~ 6% .
 Bimal K.Bose, Modern power electronics and AC drives, Prentice Hall PTR 2002
 Charles l.Hubert, Electric Machines – theory, operation, applications, adjustment, and control, PEARSON 2002
 Mellor et al ," Lumped parameter thermal model for electrical machines of TEFC design ", IEE Proceedings-B,Vol.138,No.5, April 1991
 Yangsoo Lee, "thermal analysis of induction motor with forced cooling channels", IEEE, magnetics, Vol.36, NO4, July 2000.
 Mario J. Durán, "Lumped parameter thermal model for induction motors", IEEE, energy conversion Vol.15, June 2004.
 Sreehivasan and Sengupta, "thermal design of totally enclosed fan cooled induction motors", IEEE winter PES, NY 1977.
 Dokopoulos and Xypteras, "analysis of transient temperature distribution in a rotating machine", electrical machines Sept 1982.
 Stephen J.Chapman, Electric machinery fundamentals, McGraw Hill 2005.
 Ogbonnaya I. Okoro, "Steady and Transient States Thermal Analysis of a 7.5-kw Squirrel-Cage Induction Machine at Rated-Load Operation", IEEE, energy conversion, vol. 20, no. 4, December 2005.
www.electro-tech-online.com/general-electronicschat/7587-test-inductor-motor-no- load-blocked-otortest.html35 - k
 Rosenberry, G.M.Jr.," the transient stalled temperature rise of the cast aluminum squirrel rotors for induction motors", AIEE, vol, PAS-74, Oct 1955
 Williamson and Walker, "calculation of stall bar temperature rise", 5th Int. Conf. on electrical machines and drives, Sept 1991.
 Frank P.Incropera, David P.DeWitt, Fundamentals of heat and mass transfer, John Wiley and Sons 2002.
 Ying Huai, Roderick V. N. Melnik, "Computational analysis of temperature rise phenomena in electric induction motors", Science Direct, Applied Thermal Engineering, Volume 23, Issue 7, May 2003, Pages 779-795.
 Staton D.A., Cavagnino A., "Convection Heat Transfer and Flow Calculations Suitable for Analytical Modeling of Electric Machines ", IEEE Industrial Electronics , Nov. 2006.
 Taylor, G.I.,"Distribution of Velocity and Temperature between Concentric Cylinders", Proc Roy Soc, 1935, 159, PtA, pp 546-578
 Gazley, C.: 'Heat Transfer Characteristics of rotating and axial flow between concentric cylinders', ASME, Jan 1958, pp.79-89.
 Powek Witzak, "the transient heat flow in stator of the high voltage induction motor", evolution and modern aspects of induction machines, July 1986.
 Gnffith and McCoy," induction motor squirrel cage rotor winding thermal analysis", IEEE, Vol.-EC-1, N-3, sept 1986.
 Yuangjiang Liu," 3D thermal stress analysis of the rotor of an induction motor", IEEE, magnetics, Vol. 36, NO4, July 2000
 Siyambalapitiya et a1," transient thermal characteristics of induction motor rotor cage ", IEEE, V-3, N-4, Dec 1988.
 Rajagopal et al," Axi-symetric steady state thermal analysis of totally enclosed fan cooled induction motors using FEM", CAD/CAM ,Aug 1994.
 J. K. Al-Tayie and P. P. Acarnley, “Estimation of speed, stator temperature and rotor temperature in cage induction motor drive using the extended Kalman filter algorithm,” IEE Proc. - Electr. Power Appl., vol. 144, pp. 13-20, 1997.
 Shenkman, “ Thermal behaviour of induction motors under different speeds” IEE Proc., Electr. Power Appl, Volume 152,September 2005.