Grid connected photovoltaic energy storage system: The electricity generated by photovoltaic energy can be used during the day and night, and distributed measurement is generally used during the day, while the electricity from the grid is still used at night. After adding energy storage, the energy storage system can be discharged at night. The grid connected photovoltaic power generation system is directly connected to the distribution network, and electricity is directly input into the grid. Currently, there is no energy storage system configured. With the serious phenomenon of "abandoning light and limiting electricity" in photovoltaic power generation and the increasing restrictions on the utilization and promotion of renewable energy due to factors such as large fluctuations in the power output of photovoltaic power generation systems, configuring energy storage in grid connected photovoltaic systems has become one of the directions for large-scale energy storage systems.

Smoother electricity output: Photovoltaic power generation is the process of converting solar energy into electrical energy, and its output power is greatly affected by environmental factors such as solar radiation intensity and temperature. In addition, as the photovoltaic power output is DC current, it needs to be converted into AC power through an inverter before being connected to the power grid. During the inverter process, harmonics will be generated. The instability of photovoltaic power and the existence of harmonic waves will cause an impact on the power grid due to the integration of photovoltaic power. Therefore, an important purpose of configuring energy storage in grid connected photovoltaic power generation systems is to smooth the output of photovoltaic power and improve the quality of photovoltaic power.