Smoothing Control Strategy of Hybrid Energy Storage System Based on Kalman Filter and Empirical Mode Decomposition

In view of the fluctuation of wind farm output power, this paper proposes a smoothing control method of hybrid energy storage system based on Kalman filter and empirical mode decomposition, which is based on the actual wind farm power data. Firstly, the Kalman filter is used to obtain the target grid-connected power and the total smoothing power control signal of the energy storage system. Then, considering the working characteristics of different energy storage media of Hybrid Energy Storage System (HESS), Empirical Mode Decomposition (EMD) is used to obtain each intrinsic mode component within the allowable range of charging and discharging frequency, and the Hilbert transform is used to obtain the main frequency of the energy storage power signal, so as to determine the filtering time constant and assign the high-frequency fluctuation to the super capacitor. The low frequency fluctuation is borne by the battery. Finally, the effectiveness and accuracy of the method are verified by simulation. The simulation results show that this method can effectively suppress the power fluctuation of wind farm, which is of great significance to improve the power quality of wind power integration and enhance the stability of power system.