Energy storage control technology is one of the development cores of the micro-grid. In the photovoltaic and wind power generation with insufficient stability

the optimal control strategy of energy storage can enhance the ability of smooth power fluctuation of the system. In view of lacking inertial buffer of power interface in the wind-solar micro-grid and big response shock in case fluctuation of the system

it is studied to introduce the inertial and damping characteristics of rotating motor into the control of energy storage

so to keep the energy storage possess the robustness of rotating motor and increase interference resistance ability of the system. The optimal control strategy for control ling the charge and discharge of the battery is proposed for the needed power distribution in accordance with battery charge status

so to void the excess charge and discharge of the battery and extend service life of the battery. The ability of the control strategy to optimize the energy storage performance and improve reliability of system operation is verified by the small signal analysis and system simulation.