Online state of charge estimation for a vanadium redox flow battery with unequal flow rates
Alejandro Clemente, Andreu Cecilia, Ramon Costa‐Castelló
Abstract
This study presents an observer-based methodology to estimate, in real-time, the state of charge of a Vanadium redox flow battery. Different from the available results in the literature, this work presents a new estimator that distinguishes between the concentration in the tank and cell parts of the system. Moreover, it presents an estimation of the state of charge that can deal with both balanced and unbalanced situations. The model used for the observer design is a nonlinear electrochemical model. A nonlinear observer is proposed, designed and validated through simulation and in an experimental prototype. • An observer for the estimation of the state of charge of vanadium redox flow batteries. • A technique to estimate the species concentration in all system even in conditions of low flow rates. • The estimator is validated through simulation, considering output noise. • The observer is tested and validated in a real redox flow battery prototype.