Optimal control of battery for grid-connected wind-storage system

The penetration level of large-scale wind farms is restricted by the output uncertainties of wind power generations. Energy storage systems with fast response time and high operation efficiencies, such as, flywheel and battery could be used as one of the solutions for large-scale wind power integration to power grid. To mitigate the power fluctuation of wind farm, an optimal control method of battery energy storage system is proposed for grid-connected wind system in this paper. Based on one-day ahead forecasted data of wind farm output, an optimization model is proposed to minimize the output power fluctuation as well as energy storage subject to battery capacity and power constraints. The solution algorithm is presented to solve the nonlinear optimization model. Finally, case studies with different output power curves of wind farm are presented to analyze the inter-relationship of energy storage capacity, energy storage output power and wind power fluctuation and typical configuration of battery energy storage system for wind-storage hybrid system is proposed.