Improved thermal management of electrical vehicles usinginternal magnetic field of the electric motors

Improved cooling performance is required to ensure system durability and reliability of electric motors used for electric vehicles, and using magnetohydrodynamics principles offers a promising approach to enhance cooling performance. In this study, the utilization of the internal magnetic field of a 110 kW permanent magnet synchronous motor that has six axial cooling channels embedded between the coils to improve cooling performance is presented. The magnetic field for this motor is estimated and its effect on cooling performance is identified through numerical analysis. Magnetohydrodynamic effects are achieved using Cu-water/ethylene glycol magnetic nanofluids at varying particle volume fractions (up to 1%) and volume flow rates from 25 L/min to 35 L/min. The maximum improvement in thermal performance is observed at a flow rate of 25.8 L/min with a 1% volume fraction, yielding a remarkable 64% increase in the convection heat transfer coefficient and a 21% reduction in total thermal resistance, and 20% increase in cooling capacity by utilizing the internal magnetic field effect. The utilization of magnetohydrodynamic effects leads to a notable reduction in motor temperatures, thereby enhancing the endurance limits by up to 218%. The utilization of magnetohydrodynamics effects in this study proves advantageous to enhance the overall performance of the cooling system in the motor.