Vanadium Redox Flow Battery State of Charge Estimation Using a Concentration Model and a Sliding Mode Observer

Abstract

Vanadium redox flow batteries are very promising technologies for large-scale, inter-seasonal energy storage. Tuning models from experimental data and estimating the state of charge is an important challenge for this type of devices. This work proposes a non-linear lumped parameter concentration model to describe the state of charge that differentiates the species concentrations in the different system components and allows to compute the effect of the most relevant over-potentials. Additionally, a scheme, based on the particle swarm global optimization methodology, to tune the model taking into account real experiments is proposed and validated. Finally, a novel state of charge estimation algorithm is proposed and validated. This algorithm uses a simplified version of previous models and a sliding mode control feedback law. All developments are analytically formulated and formally validated. Additionally, they have been experimentally validated in a home-made single vanadium redox flow battery cell. Proposed methods offer a constructive methodology to improve previous results in this field.

State of Charge Estimation of Lithium Sulfur Batteries using Sliding Mode Observer

“…Similarly, the adaptive neuro-fuzzy inference system (ANFIS) [7], and Support Vector Machine (SVM) [8 based Li-S SOC studied. But there is not literature on SMO for Li-S batteries though SMO were widely used for SOC estimation of Li-Ion [9][10][11]. This paper fulfills such literature gap.…”

IAE Minimization in Sliding Mode Control With Input and Velocity Constraints

“…Our further research in this topic will include ITAE quality index minimization. Moreover, the analysis can be extended to many areas, for example, the sliding line equation can be changed in such a manner to substitute the square root with a power greater than 1 2 and smaller than 1 in order to keep the system stable. Tuning this new parameter may lead to the improvement of our strategy by reducing the values of quality indexes even more.…”

“…Its main favorable properties are robustness with respect to external disturbances [10] and minimal requirements of computational power. Due to these advantages sliding mode control is frequently used in electric drives, mechanical systems, and many diverse practical systems [1]- [8], [11], [12]. The basis of this methodology has been developed in the previous century [13], [14], however it still is an active research field both from the theoretical [15] and practical [16] perspective.…”

“…One of the advantages of sliding mode observers is that the estimation error gets driven to zero in finite time [17]- [19], not asymptotically as in "traditional" observers. In [1] the problem of state of charge estimation in a vanadium redox battery is analyzed. First, a concentration model is derived and tuned using particle swarm optimization.…”

Estimación del estado de carga de baterías de flujo redox con caudales desequilibrados.

“…El modelo electroquímico utilizado se basa en los trabajos de Skyllas-Kazacos [17], siendo uno de los más utilizados y aceptados. Este modelo ha sido validado experimentalmente en trabajos previos [6].…”