An Adaptive Observer State-of-Charge Estimator of Hybrid Electric Vehicle Li-Ion Battery - A Case Study

Abstract

In this research paper we investigate the procedure design and the implementation in a real time MATLAB SIMULINK R2017a simulation environment of an accurate adaptive observer state estimator. The effectiveness of the observer state estimator design is proved through intensive simulations performed to estimate the state-of-charge of a lithium-ion rechargeable battery integrated in a hybrid electric vehicle Battery Management System structure for a particular Honda Insight Japanese car. The state-of-charge is an essential internal parameter of the lithium-ion battery, but not directly measurable, thus an accurate estimation of battery state-of-charge becomes a vital operation for the Battery Management System. This is the main reason that motivates us to find the most suitable state-of-charge estimator in terms of estimation accuracy, fast convergence and robustness to the possible changes in the state-of-charge initial value, to the temperature effects on the battery, changes in the battery internal resistance and nominal capacity.