A hybrid energy storage system(HESS)consisting of battery and super capacitor is developed to mitigate wind power fluctuation and realize smooth integration of wind power. According to the fluctuation characteristics of wind power in different output scenarios

and considering the grid regulations on wind power volatility and the performance characteristics of HESS

a novel self-adaptive wavelet packet decomposition and HESS primary power distribution method is proposed

which can yield wind power grid-connected values and HESS primary power instructions. Then the HESS primary power instruction will be given secondarymodification using fuzzy optimal control inside HESS according to the state of charge(SOC)of the super capacitor

and the final HESS power distribution instruction can be determined. Simulation results show that the proposed strategy is able to achieve optimal decomposition and rational distribution of wind power

ensure the SOC of HESS working within the reasonable range

effectively improve the smoothing effect of wind power output fluctuation

and guarantee long-term stable operation of the HESS.