Publication

OCV Estimation in electrochemical batteries with an unknown linear model and finite excitation

Journal Article (2025)

Journal

Journal of Energy Storage

Pages

117665

Volume

132

Doc link

https://doi.org/10.1016/j.est.2025.117665

File

Download the digital copy of the doc pdf document

Abstract

This study introduces a novel observer architecture for estimating the model parameters and the Open Circuit Voltage (from which State of Charge can be obtained) in electrochemical systems that can be modeled through an equivalent circuit, like lithium-ion and vanadium redox-flow batteries. The proposed methodology leverages the recently proposed Generalized Parameter Estimation Based Observer framework to transform the state estimation problem into a parameter estimation problem. This novel approach can be exploited to relax the Persistence of Excitation requirement, enabling an accurate estimation in a wider variety of scenarios. Numerical simulations across various current profiles, including one that guarantees persistent excitation and real-world driving cycles, validate the robustness of the estimator under both noiseless and noisy conditions. Experimental results from lithium-ion and vanadium redox-flow battery setups further corroborate the accuracy of the architecture, demonstrating its capability to estimate Open Circuit Voltage and reconstruct terminal voltage effectively.

Categories

observability.

Author keywords

Lithium.ion batteries, Vanadium redox-flow batteries, SoC estimation, Parameter identification, Relaxation of the persistence of excitation condition

Scientific reference

M. Marti, A. Cecilia, R. Ortega, A. Bobstov and R. Costa. OCV Estimation in electrochemical batteries with an unknown linear model and finite excitation. Journal of Energy Storage, 132: 117665, 2025.