Real-Time State of Power Estimation of a Lithium-Ion Battery Using Novel Battery Observation Model and the Recursive LS Filter

The state of power (SOP) refers to the maximum available power from a battery. The SOP is a function of the open circuit voltage and internal resistance of the battery, both of which change with the state of charge (SOC). As such, the SOP is a more informative metric of battery state than the SOC and is crucial for the continued operation of an electric vehicle. The existing approaches employ non-linear system identification techniques that are sensitive to changes in temperature and SOC. In this paper, a novel approach is proposed to estimate the state of power in real-time. The proposed approach does not require non-linear approaches for both system identification and filtering. Instead, a linear least squares estimation technique is utilized to estimate the parameters needed for SOP computation. The proposed approach utilizes a robust linear approach to account for the change in OCV in the observation window. The SOP estimates computed through the proposed approach are tested using realistic battery data collected at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$25^{\circ}$</tex> C.