The role of energy storage system in solar photovoltaic power system

11 Jan , 2022

Solar photovoltaic power systems can be divided into grid-connected photovoltaic power generation systems and stand-alone photovoltaic power generation systems according to whether they are connected to the grid.Grid-connected photovoltaic power generation system mainly refers to the photovoltaic system that is connected to the grid and receives grid dispatch, such as various centralized or distributed photovoltaic power plants. Stand-alone photovoltaic power generation system mainly refers to a variety of independent of the grid operation of photovoltaic power generation systems, such as solar street lights, rural household photovoltaic power supply, etc. collectively referred to as photovoltaic systems.


The impact of solar photovoltaic power system on the grid is mainly caused by the instability of PV power supply. From the perspective of grid safety, stability and economic operation, the grid-connected photovoltaic power generation system without energy storage will adversely affect line currents, system protection, grid economic operation, power quality and operation scheduling. The current way to solve the impact of PV power plants on the grid is to improve grid flexibility or to configure energy storage devices for grid-connected PV power plants.


The role of energy storage systems in photovoltaic power system is mainly reflected in the following aspects:


1) Ensure the stability of the system. In the photovoltaic power station system, there is a big difference between the photovoltaic output power curve and the load curve, and both have unpredictable fluctuation characteristics. The energy storage

and buffering of the energy storage system enables the system to operate even under rapid load fluctuations. Stable output level.


2) Energy reserve. The energy storage system can play a backup and transition role when photovoltaic power generation cannot operate normally, such as at night or rainy days when the battery array cannot generate electricity, then the energy storage system plays a backup and transition role, and the amount of its energy storage capacity depends on the demand of the load.


3) Improve power quality and reliability. The energy storage system can also prevent the grid fluctuations caused by the voltage spikes, voltage drops and other external disturbances on the load from causing a large impact on the system. Adopting enough energy storage systems can ensure the quality and reliability of the power output.