Standalone ESS modeling and dual-loop control using Zn-Br Redox flow battery

摘要

This paper proposes an ESS DC-DC Converter using Redox Flow Battery (RFB) for stand-alone microgrid applications. Price, safety, expandability and dynamics are crucial in ESS. Reports show that Zinc-bromine (ZnBr) RFB is the best choice in ESS. A simple electrical ZnBr RFB model is obtained from charging tests. A DC-DC converter Inductor current-DClink Voltage model is proposed for the DC microgrid. For the controller design in z-domain, the K-factor method is utilized while considering the nature of the digital controller. The control performance has been verified with simulation and hardware experiments. Lastly, a 10kW DC microgrid using RFB test result is shown.