Aiming at solving the problem of wind power fluctuation and capacity optimization of microgrid hybrid energy storage system

this paper proposes a multistage optimal capacity configuration method for hybrid energy storage system. In this method

the anti-pulse average filtering method is used to smooth the original wind power fluctuation

and combined with the advantages of empirical mode decomposition and discrete Fourier transform

the hybrid energy storage power is decomposed stage by stage. At the same time

the hybrid energy storage capacity is configured according to the decomposition results. In the first stage

the stored energy is decomposed by using the empirical mode decomposition. Through observing the decomposition result

the boundary component

high frequency and low frequency component are determined. In the second stage

the boundary component is reconstructed and decomposed by the discrete Fourier transform

and according to the annual operating cost

the optimal frequency demarcation point is ascertained

and then the sub-high frequency and sub-low frequency component are obtained. Finally

the capacity of hybrid energy storage component is configured by the distribution result. The simulation results verifies that

the proposed method can effectively avoid the influence of modal aliasing on capacity allocation in empirical mode decomposition

improve the decomposition accuracy and reduce the economic cost.