To smooth the fluctuation of wind power

an improved control strategy based on battery grouping control was proposed.The charge-discharge control principle and mathematical model of battery grouping control were given.The imbalance index of charge-discharge energy in battery grouping control was designed.According to the imbalance index

the reference output power of wind-storage system and the charge-discharge power of each battery group was dynamically adjusted.At the same time

the influence of wind power prediction error on the imbalance state of charge-discharge energy was studied.Finally

the proposed strategy was verified by Matlab/Simulink.The results show that compared with the conventional strategy

the proposed strategy can improve the imbalance of charge-discharge energy

and optimize the depth of charge-discharge of each battery group.What’s more

the proposed strategy is superior when wind power prediction error exists.