The need of a sustainable clean future has paved the way for environmental friendly\nelectric vehicle technology. In electric vehicles, overloading is limited by the maximum temperature\nrise in the electric motor. Although an improved cooling jacket design is of vital importance in\nlowering the maximum temperature of the motor, there has not been as much study in the thermal\nanalysis of motors compared to electromagnetic design studies. In this study, a three-dimensional\nsteady state numerical method is used to investigate the performance of a cooling jacket using water\nas the primary coolant of a three-phase induction motor with special emphasis on the maximum\ntemperature and the required pumping power. The effective thermal conductivity approach is\nemployed to model the stator winding, stator yoke, rotor winding and rotor yoke. Heat transfer by\ninduced air is treated as forced convection at the motor ends and effective conductivity is obtained\nfor air in the stator-rotor gap. Motor power losses, i.e., copper and iron losses, are treated as heat\ngeneration sources. The effect of bearings and end windings is not considered in the current model.\nPressure and temperature distributions under various coolant flow rates, number of flow passes and\ndifferent cooling jacket configurations are obtained. The study is successful in identifying the hot\nspots and understanding the critical parameters that affect the temperature profile. The cooling jacket\nconfiguration affects the region of maximum temperature inside the motor. Increasing the number of\nflow passes and coolant flow rate decreases maximum motor temperature but results in an increase\nin the pumping power. Of the cooling jacket configurations and operating conditions investigated,\na cooling jacket with six passes at a flow rate of 10 LPM with two-port configuration was found to be\noptimal for a 90-kW induction motor for safe operation at the maximum output.
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