Método de extração de parâmetros para modelos de circuito equivalente de baterias para veículos elétricos

Abstract

Electric vehicles have been steadily advancing in the automotive market as an alternative to traditional internal combustion vehicles, which demands the evolution of energy storage technologies. For this application, the most commonly used devices are lithium-ion batteries, although they are highly sensitive to high temperatures and transient loads. In order to avoid thermal leakage and accelerated battery aging, Battery Management Systems (BMS) are implemented for monitoring and optimizing battery discharge and recharge. To achieve this, it is necessary to implement a battery model with accuracy and low computational effort. Therefore, this article presents a parameter extraction method for battery equivalent circuit models, as well as performs a comparative analysis of the results obtained through each model. A parameter extraction methodology based on the analysis of voltage relaxation characteristics of charge pulse was implemented for internal resistance, first-order RC, and second-order RC models. The results of the study show that the largest error is approximately 1.5% between the internal resistance model and the experimental data used, throughout the region of low voltage variation.