Voltage H∞ Control of a Vanadium Redox Flow Battery

Abstract

Redox flow batteries are one of the most relevant emerging large-scale energy storage technologies. Developing control methods for them is an open research topic; optimizing their operation is the main objective to be achieved. In this paper, a strategy that is based on regulating the output voltage is proposed. The proposed architecture reduces the number of required sensors. A rigorous design methodology that is based on linear H∞ synthesis is introduced. Finally, some simulations are presented in order to analyse the performance of the proposed control system. The results show that the obtained controller guaranties robust stability and performance, thus allowing the battery to operate over a wide range of operating conditions. Attending to the design specifications, the controlled voltage follows the reference with great accuracy and it quickly rejects the effect of sudden current changes.

Comparison of charging control techniques for electrochemical energy storage systems

“…In terms of charging methods, the main advantage of VRFBs compared to other types of batteries such as lithium-ion batteries is that the control strategy can be defined considering a new variable besides from the current and voltage, which is the electrolyte flow rate. Taking this into account, a voltage control strategy for different currents is proposed in [17], consisting on a H ∞ flow rate controller.…”

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

“…Por tanto, dependiendo de la concentración de especies de cada electrolito, su valor puede variar. Como en cualquier tipo de batería o sistema de almacenamiento de energía, su medición es fundamental para garantizar el correcto funcionamiento del sistema [7], siendo también una variable utilizada para el diseño de controladores de caudal óptimos [8]. Dado que el SOC depende de la concentración de las especies, uno de los grandes campos de estudio consiste en encontrar posibles sensores para medir estas concentraciones en tiempo real.…”

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

“…Unlike other battery types, RFB are active elements and automatic control plays a very important role [5], [6]. Determining the appropriate electrolyte flow [7] and estimating the state of charge are the two main issues from the automatic control point of view. At present, the most widely used methods to estimate the state of charge (SOC) are based on measurements of the open circuit potential (OCP) [8] [9], conductivity [10], viscosity [11] or the colour of the electrolytes [12].…”