Caracterização térmica de baterias de íons de lítio sob operação de descarga em veículo elétrico

Abstract

This dissertation investigates the thermal profile of lithium-ion battery cells in an electric vehicle through dynamic simulation of the driving cycle during the battery discharge process over multiple driving cycles. The energy required to propel the vehicle was modeled using ADVISOR software in conjunction with MATLAB, enabling a comprehensive analysis of the system’s energy performance. The temperature profile of the battery cells was then calculated using the thermal computational fluid dynamics software ANSYS FLUENT. The simulation model was developed according to specifications provided by the vehicle manufacturer, ensuring that the simulated conditions were representative of real-world operation. The powertrain controls during the simulation were carefully constrained to remain within the electric vehicle’s capacity, avoiding overloading and ensuring a representation as close as possible to actual operational performance. Mathematical models were used to describe the vehicle’s longitudinal dynamics, the electric motor current, and the battery’s thermal characteristics. These models were developed considering the nonlinear characteristics of the battery during discharge, as well as the influence of state of charge, temperature, and current demand over time. This approach allowed for a more accurate modeling of the battery’s behavior under variable conditions. The powertrain system models were tested in various simulation environments to verify system behavior in specific situations related to electric vehicle usage. The results obtained demonstrated that the developed mathematical models consistently represent the thermal behavior performance of the system. Thus, this study provides valuable insights into the thermal performance of lithium-ion batteries in electric vehicles, contributing to the advancement of energy storage technology and the improvement of efficiency in electric mobility applications.