Energy efficiency increase of a vanadium redox flow battery with a power-based model

Kleinsteinberg, Björn; Sauer, Dirk Uwe (Thesis advisor); Doetsch, Christian (Thesis advisor)

Aachen : ISEA (2019, 2020)
Book, Dissertation / PhD Thesis

In: Aachener Beiträge des ISEA Vol. 136
Page(s)/Article-Nr.: 1 Online-Ressource (vi, 163 Seiten) : Illustrationen, Diagramme

Dissertation, RWTH Aachen University, 2019

Abstract

In this thesis the overall efficiency of a vanadium redox flow battery in different applications is investigated. Simple models of the vanadium redox flow battery lead to an ideal efficiency that exceeds the efficiencies observed in applications as well as the efficiencies in the manufacturer's data sheets. The developed model explains the reason for this discrepancy by considering different load profiles. Experimental data are used to parameterize the model components. The modelling of the stack using the Nernst equation contains inaccuracies which have been minimized empirically. The behavior during load pauses and the analysis of the crossover within the stack at different load states show possibilities for the optimization of the operation strategy. The individual design of the energy storage system for each application can increase the overall efficiency. For this purpose, a modular design of the energy storage system with optimized dimensioning of the components was modeled and simulated.