Modeling and Performance Analysis of Redox-Flow Battery Unit for Large-Scale Hybrid Renewable Energy Systems

As the demand of electric power generation has increased vastly across the world, the requirement of upgraded schemes for efficient power extraction and bulky storage has burgeoned tantamountly. To adopt the randomness and best uti-lization of the renewable energy sources, power profile prediction and energy management of large-scale solar and wind farms are major concerns for grid operators. A bulk efficient energy storage system may eliminate the issues related to unpredictability of sustainable power sources. Mostly conventional deep cycle lead-acid battery banks are utilized to meet massive storage requirement in solar and wind farms. However, the high cost, extensive maintenance, requirement of extra space and relatively short lifetime are the major shortcomings of lead-acid batteries. On the other hand, the development of Vanadium Redox-flow battery (VRFB) makes it possible to be utilized for large-scale storage because of its viable chemical composition, compact energy density and long lifecycle. In this paper, a multiphysics model of a 8 MW-h Vanadium redox-flow battery is developed for large-scale storage. The features of the VRFB have been analyzed for variation of its key parameters. To observe the effectiveness of the proposed model, a 3 MW grid-connected hybrid renewable power system consisting of photovoltaic (PV) panels and wind turbines is simulated with proposed storage unit. The battery framework is designed in COMSOL Multiphysics platform and dynamic simulations are performed in MATLAB/Simulink en-vironment. The results show that the proposed model exhibits compatible performance in managing the energy flow from the hybrid sources towards the load by maintaining the real power demanded by the grid operator.