Transient Behavior of Redox Flow Battery Connected to Circuit Based on Global Phase Structure

TL;DR

This paper analyzes the transient behaviors of redox flow batteries using a chemical kinetics-based model, revealing complex oscillations and dynamics due to load variations, which are crucial for their application in power grid stability.

Contribution

It introduces a chemical kinetics-based simulation model to analyze transient behaviors of RFBs, highlighting complex oscillations caused by load changes.

Findings

Identified three typical transient behaviors including oscillations.

Showed that complex dynamics arise from interactions of slow and fast system responses.

Demonstrated the importance of chemical kinetics in modeling RFB transients.

Abstract

A Redox Flow Battery (RFB) is one of the promising energy storage systems in power grid. An RFB has many advantages such as a quick response, a large capacity, and a scalability. Due to these advantages, an RFB can operate in mixed time scale. Actually, it has been demonstrated that an RFB can be used for load leveling, compensating sag, and smoothing the output of the renewable sources. An analysis on transient behaviors of an RFB is a key issue for these applications. An RFB is governed by electrical, chemical, and fluid dynamics. The hybrid structure makes the analysis difficult. To analyze transient behaviors of an RFB, the exact model is necessary. In this paper, we focus on a change in a concentration of ions in the electrolyte, and simulate the change with a model which is mainly based on chemical kinetics. The simulation results introduces transient behaviors of an RFB in a response to a load variation. There are found three kinds of typical transient behaviors including oscillations. As results, it is clarified that the complex transient behaviors, due to slow and fast dynamics in the system, arise by the quick response to load.