Interest in the advancement of energy storage methods have risen as energy production trends toward renewable energy sources. Vanadium redox flow batteries (VRFB) are one of the emerging energy storage techniques being developed with the purpose of effectively storing renewable energy. There are currently a limited number of papers published addressing the design considerations of the VRFB, the limitations of each component and what has been/is being done to address said limitations. This review briefly discusses the current need and state of renewable energy production, the fundamental principles behind the VRFB, how it works and the technology restraints. The working principles of each component are highlighted and what design aspects/cues are to be considered when building a VRFB. The limiting determinants of some components are investigated along with the past/current research to address these limitations. Finally, critical research areas are highlighted along with future development recommendations.

Vanadium redox flow batteries: A comprehensive review

Summary
Flow batteries have unique characteristics that make them especially attractive when compared with conventional batteries, such as their ability to decouple rated maximum power from rated energy capacity, as well as their greater design flexibility.

The vanadium redox flow batteries (VRFB) seem to have several advantages among the existing types of flow batteries as they use the same material (in liquid form) in both half-cells, eliminating the risk of cross contamination and resulting in electrolytes with a potentially unlimited life.

Given their low energy density (when compared with conventional batteries), VRFB are especially suited for large stationary energy storage, situations where volume and weight are not limiting factors. This includes applications such as electrical peak shaving, load levelling, UPS, and in conjunction with renewable energies (e.g. wind and solar).

The present work thoroughly reviews the VRFB technology detailing their genesis, the basic operation of the various existing designs and the current and future prospects of their application. The main original contribution of the work was the addressing of a still missing in-depth review and comparison of existing, but dispersed, peer reviewed publications on this technology, with several original and insightful comparison tables, as well as an economic analysis of an application for storing excess energy of a wind farm and sell it during peak demand. The authors have also benefited from their background in electric mobility to carry out original and insightful discussions on the present and future prospects of flow batteries in mobile (e.g. vehicle) and stationary (e.g. fast charging stations) applications related to this field, including a case study.

Vanadium redox flow batteries are currently not suitable for most mobile applications, but they are among the technologies which may enable, when mature, the mass adoption of intermittent renewable energy sources which still struggle with stability of supply and lack of flexibility issues.Copyright © 2014 John Wiley & Sons, Ltd.

Vanadium redox flow batteries: a technology review

Gravitational Search Algorithm (GSA) is an optimization method inspired by the theory of Newtonian gravity in physics. Till now, many variants of GSA have been introduced, most of them are motivated by gravity-related theories such as relativity and astronomy. On the one hand, to solve different kinds of optimization problems, modified versions of GSA have been presented such as continuous (real), binary, discrete, multimodal, constraint, single-objective, and multi-objective GSA. On the other hand, to tackle the difficulties in real-world problems, the efficiency of GSA has been improved using specialized operators, hybridization, local search, and designing the self-adaptive algorithms. Researchers have utilized GSA to solve various engineering optimization problems in diverse fields of applications ranging from electrical engineering to bioinformatics. Here, we discussed a comprehensive investigation of GSA and a brief review of GSA developments in solving different engineering problems to build up a global picture and to open the mind to explore possible applications. We also made a number of suggestions that can be undertaken to help move the area forward.

A comprehensive survey on gravitational search algorithm

Adaptive estimation of state of charge and capacity with online identified battery model for vanadium redox flow battery

Online state of charge and model parameter co-estimation based on a novel multi-timescale estimator for vanadium redox flow battery

Electrical Circuit Model of a Vanadium Redox Flow Battery Using Extended Kalman Filter

In this paper, a theoretical study on extended Kalman filter (EKF)-based mobile robot localization with intermittent measurements is examined by analysing the measurement innovation characteristics. Even if measurement data are unavailable and existence of uncertainties during mobile robot observations, it is suggested that the mobile robot can effectively estimate its location in an environment. This paper presents the uncertainties bounds of estimation by analysing the measurement innovation to preserve good estimations although some measurements data are sometimes missing. Theoretical analysis of the EKF is proposed to demonstrate the conditions when the problem occurred. From the analysis of measurement innovation, Jacobian transformation has been found as one of the main factors that affects the estimation performance. Besides that, the initial state covariance, process and measurement noises must be kept smaller to achieve better estimation results. The simulation and experimental results obtained a...

Extended Kalman filter-based mobile robot localization with intermittent measurements

Assembly sequence planning (ASP) becomes one of the major challenges in product design and manufacturing. A good assembly sequence leads to reduced costs and duration in the manufacturing process. However, assembly sequence planning is known to be a classical NP-hard combinatorial optimization problem; ASP with many product components becomes more difficult to solve. In this paper, an approach based on a new variant of the gravitational search algorithm (GSA) called the rule-based multi-state gravitational search algorithm (RBMSGSA) is used to solve the assembly sequence planning problem. As in the gravitational search algorithm, the RBMSGSA incorporates Newton’s law of gravity, the law of motion, and a rule that makes each assembly component of each individual solution occur once based on precedence constraints; the best feasible sequence of assembly can then be determined. To verify the feasibility and performance of the proposed approach, a case study has been performed and a comparison has been conducted against other three approaches based on simulated annealing (SA), a genetic algorithm (GA), and binary particle swarm optimization (BPSO). The experimental results show that the proposed approach has achieved significant improvement in performance over the other methods studied.

/pdf/an-assembly-sequence-planning-approach-with-a-rule-based-2exna3k9go.pdf

An Assembly Sequence Planning Approach with a Rule- Based Multi-State Gravitational Search Algorithm

In this paper, mathematical modelling of oxidation-reduction redox potential for estimating the state-ofcharge of V-RFB is presented. The estimation is based on the Nernst equation, a mass balance, Faraday’s law of electrolysis, and 1 st order kinetic equation. The 25-100 cm 2 laboratories, unit cell V-RFB is chosen as a model reaction for electrolyte redox potential measurement. Preliminary experiment is carried out using a 100 cm 2 laboratory unit but the estimated value produced is inaccurate. An alternative design of 25 cm 2 laboratory, unit cell V-RFB using a divided, open-circuit potentiometric cell is used. The redox potential of V(III)/V(II) and V(IV)/V(V) is measured through combined Hg/Hg 2 SO 4 reference electrode and carbon rod working electrode. The differences between the experimental and estimated values are highlighted. DOI: http://dx.doi.org/10.5755/j01.eee.19.3.1623

/pdf/estimating-the-state-of-charge-of-all-vanadium-redox-flow-mi2pnk6bqp.pdf

Estimating the State-of-Charge of All-Vanadium Redox Flow Battery using a Divided, Open-circuit Potentiometric Cell

Vanadium redox flow battery (V-RFB) has been attracted by many researches; some are under field testing and demonstration stage, but information on construction, experimental characterization, electrolyte preparation, overall systems under study, etc. are still limited. This paper focus on the technical issues faced and the lessons learnt during the development of unit cell and system for V-RFB. Firstly, brief description on problem identification, development and implementation in cell design and system for V-RFB are discussed. Secondly, preliminary experiment on 25 cm2 laboratory, unit cell V-RFB presents various difficulties such as its high tendency to fall under failure mode are presented. Finally, discussion on experimental result which shows significant improvement on V-RFB system efficiency up to 72% with reduction of contact resistance, recorded an average of 8.6 mΩ. In addition, the newly developed system provides a constructive base for future studies in temperature-controlled system and a divided, open-circuit potentiometric cell for half-cell redox analysis.

/pdf/design-and-development-of-unit-cell-and-system-for-vanadium-232qeiqgf2.pdf

Hamzah Ahmad

Papers

Electrical Circuit Model of a Vanadium Redox Flow Battery Using Extended Kalman Filter

Extended Kalman filter-based mobile robot localization with intermittent measurements

An Assembly Sequence Planning Approach with a Rule- Based Multi-State Gravitational Search Algorithm

Estimating the State-of-Charge of All-Vanadium Redox Flow Battery using a Divided, Open-circuit Potentiometric Cell

Design and Development of Unit Cell and System for Vanadium Redox Flow Batteries (V-RFB)