Research On Wind Power Fluctuation Suppression Based On Hybrid Energy Storage Syste

The large-scale exploitation and use of traditional energy result in the depletion of natural resources and the deterioration of the environment,which being a serious constraint to the sustainable development of our society.We need to implement electric energy substitution and accelerate the development and utilization of clean energy.China has abundant wind power resources,wind power generation technology is relatively mature,coupled with the support of a series of national wind power development policies,the installed scale of wind power in China is increasing day by day.As the penetration rate of wind power increases,the threat posed by the instability and volatility of wind power to the safety and stability of the power system will also increase.In this context,with the goal of reducing the negative impact of wind power grid-connection on the power system,this paper focuses on hybrid energy storage system to achieve wind power fluctuation stabilization,and strives to reduce wind power fluctuation through accurate power prediction and reasonable power distribution of hybrid energy storage system.The main work overview is as follows:Firstly,according to the characteristics of wind speed and wind power of wind farm,it is introduced in detail and verified by simulation that Variational Mode Decomposition has higher time-frequency resolution than Empirical Mode Decomposition and Ensemble Empirical Mode Decomposition,and has more advantages in nonlinear data processing,which provides a good data processing method for the establishment of wind power time series prediction model.Secondly,a combination model based on Variational Modal Decomposition is proposed to optimize the parameters of Long Short-Term Memory network by Sparrow Search Algorithm,and the MATLAB simulation results of different prediction models are compared with the prediction evaluation index as the judgment standard,and the complexity and modeling difficulty of the model input time series data are relatively reduced after processing by Variational Modal Decomposition method,which improves the accuracy of wind power prediction.Then,in order to avoid the adverse effects of excessive wind power output fluctuation on the power grid,a hybrid energy storage system based on power prediction was proposed to smooth the wind power fluctuation.By analyzing the working principle of supercapacitor and lithium battery and the advantages and disadvantages of different topologies,the topology structure of wind power-hybrid energy storage combined system is determined.Based on the frequency domain analysis results of wind power data,the damping target power of hybrid energy storage system meeting the standards of wind power grid-connection was obtained by combining discrete wavelet and wind power prediction.The charge and discharge instructions of the hybrid energy storage system are determined according to the power relationship.Finally,combined with the characteristics of different energy storage devices,the internal power distribution method of the hybrid energy storage system based on empirical wavelet and Hilbert marginal spectrum is proposed.Based on the capacity configuration results of the energy storage device,the life cycle cost of the hybrid energy storage system is calculated.The fuzzy control strategy of hybrid energy storage system considering the state of charge of energy storage device is proposed to complete the power correction,and the feasibility of the power prediction assisted hybrid energy storage system to smooth the wind power fluctuation is verified by simulation,which provides a certain reference for improving the controllability of wind power grid-connection.