Battery Management System in Electric Vehicle for Energy Storage System Using Extended Kalman Filter and Coulomb Counting Methods

Abstract

The global advancement in battery technology for electric vehicle (EV) applications is crucial in addressing global warming and reducing carbon emissions. The effectiveness of EVs and the functionality of battery storage systems hinge on the precise evaluation of critical parameters. However, inadequate safety measures and improper monitoring of battery systems can lead to significant issues such as overcharging, over-discharging, overheating, cell imbalance, and fire hazards. This research presents an efficient Battery Management System (BMS) designed to enhance battery performance by accurately monitoring and regulating charging and discharging processes, managing heat generation, and ensuring safety and protection. Given that batteries are fundamental to the sustainable mobility offered by electric vehicles, lithium-ion (Li-ion) batteries are recognized as the leading energy storage technology. Yet, challenges remain in selecting optimal cell materials and developing advanced electronic circuits and algorithms for efficient battery utilization. One critical challenge is the accurate estimation of a Li-ion battery's state of charge (SOC), due to its complex, time-variant, and nonlinear electrochemical nature. This study proposes the use of an Extended Kalman Filter (EKF) for SOC estimation, analyzing the Coulomb counting method to calculate the remaining battery capacity. The research on Battery Management Systems in Electric Vehicles using Extended Kalman Filter and Coulomb Counting methods showed improved state-of-charge estimation with an accuracy of ± 2% and enhanced energy efficiency, optimizing battery performance and lifespan. A closed-loop optimization algorithm is introduced for supervisory logic and fault detection. The EKF is employed to maintain the supercapacitor's SOC within the desired range. Simulation results demonstrate that the proposed control strategy effectively reduces the maximum charge/discharge currents, thereby enhancing battery lifespan.