Hybrid energy storage control for smoothing wind power fluctuations considering energy storage output levels

Due to the unique features of wind power, such as intermittency, randomness, and volatility, the integration of wind power into the grid on a large scale has a significant impact on the safety and stability of the power system. Hybrid energy storage systems can effectively handle complex wind power fluctuations, mitigate grid-connected power fluctuations, and increase the penetration rate of wind power in the power grid. This article presents a hybrid energy storage smoothing control method that considers the output level of energy storage to suppress wind power fluctuations. To meet the smoothing requirements, a hybrid energy storage smoothing model based on model predictive control is developed. Firstly, model predictive control (MPC) is employed, with the objective functions of minimizing the energy storage output and balancing the charging and discharging of energy storage, to solve the entire range of mixed energy storage. Then, the total range is divided into the battery range and the supercapacitor range using adaptive sliding filtering. This ensures that the supercapacitor operates on the portion with a higher rate of change in the control sequence, while the battery handles the smoother part of the control sequence. Finally, simulations were conducted based on actual wind field data to verify that the proposed strategy can effectively strike a balance between energy storage life and wind power fluctuations, as well as reduce the downtime of energy storage batteries.