State-of-charge estimation for Li-ion batteries with uncertain parameters and uncorrelated/correlated noises: a recursive approach

In this paper, the recursive state-of-charge (SOC) estimation problem is investigated for the Li-ion batteries. The uncertain parameters, which are used to account for the effects of the changing temperatures, the battery power and the drift current of current sensors, are considered in the modelling process of the Li-ion batteries. Moreover, the uncorrelated/correlated noises are also considered based on the engineering practice. The aim of the paper is to design a SOC estimation scheme such that an upper bound on the estimation error covariance is guaranteed, and such an upper bound is then minimised by appropriately designing the estimator gain. Finally, simulation experiments are carried out to demonstrate the effectiveness of our proposed SOC estimation scheme.