Flow battery energy storage system for microgrid peak shaving based on predictive control algorithm

Abstract

Energy storage system is an important component of the microgrid for peak shaving, and vanadium redox flow battery is suitable for small-scale microgrid owing to its high flexibility, fast response and long service time. Therefore, a microgrid based on vanadium redox flow battery is studied for rural applications in this paper, in which biomass gasification and solid oxide fuel cell are integrated as power generation units to provide stable electricity. A predictive control method is presented to improve the efficiency of flow battery and the economic feasibility of this system is evaluated. The mathematical model is validated with the experimental data of published literature. The results indicate that controlling the electrolyte flow rate according to the current and the state of battery can reduce the energy loss of flow battery. The optimal electrolyte flow rate is determined by predictive control method, which can significantly improve the performance of flow battery compared with previous method. The overall efficiency of battery for peak shaving is achieved by 84% and the pay back period of this microgrid system is 7.33 year.