Estimation of the state of charge and diffusion coefficients in redox flow batteries.

This paper presents an observer for the estimation of the state of charge of redox flow batteries. The observer is high gain and is based on a non-linear dynamic model, which uses a realistic approach differentiating between the total electrolyte concentrations in the two parts of the system. It is shown that the state of charge can be estimated by measuring cell voltage and a high gain observer. However, the precision of the estimate is affected by the uncertainty in the diffusion coefficients of the system. For this reason, the observer is strengthened by estimating adaptive parameters of immersion and invariance. Finally, the results are validated in a numerical simulation.


observability, storage automation.

Author keywords

Redox flow batteries, state of charge, adaptive nonlinear observer

Scientific reference

A. Clemente, A. Cecilia and R. Costa. Estimación del estado de carga y coeficientes de difusión en baterías de flujo redox, XLII Jornadas de Automática, 2021, Castellón, Spain, pp. 357-364.