Hybrid Energy Storage Fluctuation Smoothing Strategy Based on Modal Decomposition Algorithm

The hybrid energy storage system (HESS) combining an all-vanadium redox flow battery and a hybrid supercapacitor can effectively stabilize wind power fluctuations. In order to enhance the flexibility and security of the energy storage system, a hybrid energy storage power allocation method based on Parameter-optimized variational mode decomposition (VMD) and empirical mode decomposition (EMD) is proposed. Firstly, the original wind power signal is decomposed into direct grid-connected component and HESS power task by EMD. Then, the sparrow search algorithm (SSA) is used to optimize the modal number K and the quadratic penalty factor a in the VMD algorithm. After obtaining the optimized K value and a value, the VMD algorithm is used to decompose the wind power fluctuation power and complete the basic distribution between the all-vanadium flow battery and the hybrid super capacitor. Finally, the MATLAB / YALMIP is used to call the GUROBI / CPLEX solver to solve the configuration results, and the effectiveness and economy of the proposed strategy in stabilizing fluctuations are verified. The findings demonstrate that in addition to adaptively decomposing the wind power fluctuation power signal, effectively suppressing wind power fluctuation, and reducing modal aliasing, the suggested method can also take into account the energy characteristics of various energy storage devices to complete the reasonable distribution of HESS power, take advantage of the inherent advantages, and improve the system's overall efficiency.