Thermal Analysis of a Magnetic Contactor in Electric Vehicle Li-Ion Battery Packs

In this paper, we perform 3D numerical simulations to understand the thermal operation of a high-current-load DC Magnetic Contactor (MC) within a Li-ion battery pack. The main focus is on evaluating the thermal behavior of an electronically controlled MC through a parametric study that investigates the effect of the magnitude of electric current with the corresponding Ohmic heat generation of the MC. For the numerical analysis we perform time-accurate, conjugate heat transfer-based 3D CFD simulations on high spatial resolution grids with commercial CFD software STAR-CCM+. The results of the numerical simulations with temperature dependent material properties are validated against experimental temperature measurements at various locations on the outer body of the MC. The spatial distribution of temperature, and current within the MC and its connected components are also computed for various input parameter values to evaluate a range of its operational validity within an automotive Li-ion battery pack.