Abstract: A new dual-battery wind energy storage system is proposed,which can maintain the fluctuation of wind power within a specified range at a lower operating cost. Wind farms can output constant power in each dispatching period,so that wind power can be stably integrated into the grid. When the dispatching power is lower than the actual wind power,the batteries with charging function are in working state,and when the dispatching power is higher than the actual wind power,the batteries with discharging function are in working state,when one of the batteries is full or deep discharging,the charging and discharging states of the two batteries are switched.To prolong the service life of batteries,the dispatching power is optimized to ensure that both batteries operate under complete charging and discharging cycles. This dual-battery energy storage system can significantly reduce the operating cost of the system. A 3 MW wind turbine with real wind power data is simulated and analyzed,and the effectiveness of the proposed system and control strategy is verified.