In recent years, photovoltaic power generation technology has advanced rapidly, and the installed capacity has increased rapidly. However, photovoltaic power generation has shortcomings such as intermittent and uncontrollable. Before processing, large-scale direct access to the power grid will bring great impact and affect the stable operation of the power grid. Adding the energy storage can make the photovoltaic power generation smoothly and stably output to the power grid, and the large-scale access to the power grid will not affect the stability of the power grid. And photovoltaic + energy storage, the system has a wider range of applications.