A control strategy for smoothing the fluctuation of wind power grid connection based on hybrid energy storage system

The stochastic volatility of wind power generation has an impact on grid stability, and a hybrid energy storage system (HESS) based on parameter optimization with variational mode decomposition (VMD) is proposed to suppress the fluctuation of wind power on the grid. control strategy. Firstly, the VMD method optimized by the sparrow search algorithm (SSA) is used to decompose the fluctuating power of wind power that needs to be suppressed. According to the obtained spectrogram, based on the energy ratio of each sub-module and the minimum modal overlap, the high and low-frequency power is allocated to the supercapacitor and lithium battery to realize the distribution of power in the hybrid energy storage system. Secondly, to prolong the service life of the energy storage system and prevent the overcharge and over-discharge phenomenon from damaging the energy storage components, the power of the energy storage components is corrected by fuzzy control rules. Finally, the method proposed in this paper is applied to wind power data collected in a region, and the experimental results show that the strategy can effectively smooth out the fluctuation of wind power grid connection, reduce the degree of fluctuation of the charge state of the energy storage system, and realize the stable operation of the hybrid energy storage system.