With the increasing proportion of photovoltaic power system in energy supply, independent photovoltaic power generation is random, intermittent and volatile, and it will affect the safe and stable operation of the system. In order to ensure the safety and stability of the grid system containing photovoltaic, The quality of power, It is necessary to provide a certain amount of energy storage in photovoltaic power generation to achieve the stable operation of the grid system and improve the utilization rate of photovoltaic. At the same time, it can also play the role of "cutting peak filling" and reduce the user's electricity cost, which has a good economy.