Study on operating conditions of household vanadium redox flow battery energy storage system

Abstract

A 10 kW household vanadium redox flow battery energy storage system (VRFB-ESS), including the stack, power conversion system (PCS), electrolyte storage tank, pipeline system, control system, etc., was built to study the operation conditions. The VRFB-ESS has been run at different current density. And the system performance was further studied, including system charge & discharge energy, stack polarization voltage, the energy consumption of each unit etc. The experimental results showed that when running at 74 A (current density 150 mA·cm−2), the energy storage system can charge 24.9 kWh and discharge 15.2 kWh, with a system efficiency of 61.0%. While the system energy consumption accounts for 39%, of which 6.03% is consumed by the pump, 10.99% by the PCS, 16.26% by the internal resistance of the stack, 4.66% by the pipeline, and 1.06% by the control system. stack has good stability, and the temperature of the system only rises 1.6 ℃. The experiment provides effective data support for the subsequent improvement of system performance.