A H∞ Switched Singular Observer for the State of Charge Estimation in Lithium-Ion Batteries

The most essential component of battery behavioral analysis is the precise and trustworthy calculation of lithium batteries’ state of charge (SOC). In this paper, a H ∞ switched singular observer is proposed for determining the state of charge (SOC) of lithium-ion batteries. Utilizing the equivalent circuit model (ECM) and considering the open-circuit voltage as an additional state variable, a new switched singular model is introduced for the lithium-ion batteries. This model offers a compromise between accuracy and complexity in SOC estimation. Based on this model, a H ∞ switched singular observer is designed to guarantee the exponential convergence of the estimated SOC to its real value in the presence of uncertainties. The design parameters are calculated by solving linear matrix inequalities derived using the average dwell time (ADT) method. The simulation results are presented to demonstrate the effectiveness of the proposed observer.