A restricting condition on transient behavior of redox flow battery in phase space

Abstract

Power storage systems are expected to contribute the stable power distribution under disturbances in power systems. Recently, power quality such as momentum voltage sag is a critical issue for power systems. For maintaining power quality, battery is inevitable and expected to quickly respond to the disturbances in the power systems. Redox Flow Battery (RFB) is one of the batteries which is capable to compensate the disturbance rapidly. The response of RFB is governed by the chemical, fluid and electrical dynamics with multiple time scales. The fast dynamics of external circuit has been neglected in the discussion of modeling. In this paper, we discuss the limitation of the transient behavior based on the phase space analysis with a previously proposed model. Here is, in particular, focused on the discussion of the parameters related to the flow of the electrolysis solution. As a result, it is clarified that the transient behavior is forcedly bound by the external electrical circuit at the load change, and the flow of the electrolysis solution pushed the increase of the consumption of ions down.