Optimization And Control Of Hybrid Energy Storage Capacity Configuration For Wind Farm

Under the target of "double carbon",the new energy industry represented by wind power is developing vigorously.However,with the increase of wind power permeability,the volatility of wind energy itself has brought great challenges to the safety of grid connection.It is an effective solution to solve the above problems to allocate a certain capacity energy storage system in wind farms.In this paper,a hybrid energy storage system composed of lithium-ion battery and supercapacitor is adopted to focus on the selection of typical wind power day,control strategy to smooth wind power fluctuations and hybrid energy storage capacity optimization configuration model.Firstly,the improved fuzzy clustering algorithm is used to select the typical daily curve which can best represent the original wind power output characteristics,and then the typical daily curve is filtered by exponential smoothing method to get the target power instruction of the hybrid energy storage system.The complete ensemble empirical mode decomposition with adaptive noise and Hilbert transform were used to decompose and reconstruct the hybrid energy storage power instructions.The high and low frequency power instructions were allocated to the supercapacitor and lithium-ion battery respectively.Then the charge and discharge power of lithium-ion battery and supercapacitor is corrected by using the fuzzy control based on the state of charge,so as to maintain the state of charge of energy storage within the safe range,finally,the rational distribution of unbalanced power in the hybrid energy storage system is realized.Then,a life-cycle capacity configuration model of hybrid energy storage system considering the cycle life of lithium-ion battery was established.The model calculated the battery depth of discharge by using the rainflow counting method.The minimum average annual cost of hybrid energy storage system was taken as the objective function,and the optimal capacity configuration was obtained under various constraints.Finally,the visualization simulation software of wind farm hybrid energy storage system is designed to study the control strategy and capacity allocation method in this paper.