Nonlinear observer for online concentration estimation in vanadium flow batteries based on half-cell voltage measurements

This paper presents a nonlinear observer to estimate the active species concentrations in vanadium flow batteries. To conduct the estimation, the observer relies only on current, flow rate and two half-cell voltage measurements. In contrast to previous works in the field, the proposed observer is ca...

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Detalles Bibliográficos
Autores: Puleston, Thomas Paul|||0000-0003-3251-7533, Cecilia Piñol, Andreu|||0000-0002-5579-4157, Costa Castelló, Ramon|||0000-0003-2553-5901, Serra, Maria|||0000-0002-9885-8093
Tipo de recurso: artículo
Fecha de publicación:2024
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/404918
Acceso en línea:https://hdl.handle.net/2117/404918
https://dx.doi.org/10.1016/j.compchemeng.2024.108664
Access Level:acceso abierto
Palabra clave:Storage batteries
Electrolytes
Vanadium flow batteries
Nonlinear observer
State of Charge
Battery monitoring
Electrolyte imbalance
Acumuladors
Electròlits
Àrees temàtiques de la UPC::Informàtica
Àrees temàtiques de la UPC::Enginyeria electrònica
Descripción
Sumario:This paper presents a nonlinear observer to estimate the active species concentrations in vanadium flow batteries. To conduct the estimation, the observer relies only on current, flow rate and two half-cell voltage measurements. In contrast to previous works in the field, the proposed observer is capable to deal simultaneously with two significant and challenging conditions: (1) a not necessarily high flow rate, which results in different concentrations for tanks and cells, and (2) presence of crossover and oxidation side reactions, that result in imbalance between the electrolytes on the positive and negative sides of the system. The stability and convergence of the observer are formally demonstrated using a Lyapunov analysis and subsequently validated through comprehensive computer simulations. Finally, utilising the information provided by the observer, a strategy to independently regulate the flow rate of each electrolyte based on their individual state of charge is developed.