Thermal Sensitivity Analysis of a liquid-cooled stator in a PM motor using CFD

Electric Vehicles (EVs) are the solution to the current problem of climatic change due to environmental pollution, thereby conserving the environment. The need for faster adoption of EVs has gained massive importance in the field of e-mobility, and intense research is going on to launch it on a large scale of applications. The thermal management of the motor in an EV is an essential aspect because the electrical insulation has a temperature limit, affecting its efficiency. As part of the motor development, Flow and Conjugate Heat Transfer (CHT) analysis of the liquid-cooled stator has been carried out using Computational Fluid Dynamics (CFD). CFD bestows the advantage of visualizing the flows and temperature distributions in 3D. This paper deals with the thermal sensitivity analysis of the coolant flow path to study the various parameters affecting the flow in the stator. CHT studies are done by modelling all the fluid and solid domains. The effect of the mass flow rate of coolant, coolant inlet temperature, type of coolant, and heat loss on thermal parameters such as heat transfer coefficient (HTC), coolant temperatures, winding temperatures, and stator temperatures are discussed. The predicted flow and temperature results have been validated with the experimental test data, and the CFD results were within 3% of the experimental data.