On Grid Energy Storage System Introduction
On Grid energy storage system is a type of power system that connects energy storage devices to the grid, enabling bidirectional flow of electrical energy and enabling coordinated operation with the grid. The following is a detailed introduction to it:
1.Main components
Energy storage devices: Common types of batteries include lithium-ion batteries, lead-acid batteries, sodium sulfur batteries, etc; There are also supercapacitor energy storage, pumped storage, compressed air energy storage, flywheel energy storage, etc.
Power conversion devices: mainly inverters and bidirectional converters. The inverter converts the DC power output from the energy storage battery into AC power, and the bidirectional converter can achieve bidirectional conversion of electrical energy, controlling the charging and discharging process of the energy storage system.
Control management system: Real time monitoring and control of the operation status of the energy storage system. Based on the demand of the power grid and the status of the energy storage system, the optimal charging and discharging strategy is formulated and executed to ensure the safe, stable, and efficient operation of the system. It can also achieve communication and interaction with the power grid dispatch system.
Measurement and protection device: The measurement device is used to measure parameters such as electricity and power of the energy storage system, providing data support for billing and operation management. The protective device promptly cuts off the circuit in case of abnormal conditions such as overcurrent, overvoltage, undervoltage, overheating, etc. in the system, protecting the safety of equipment and personnel.
2.Working principle
Charging process: When the power grid is in a low load or there is an excess of renewable energy generation, the energy storage system absorbs electrical energy from the grid or stores the excess electricity generated by renewable energy, converts the electrical energy into chemical energy, and stores it in the energy storage device.
Discharge process: In situations such as peak load on the power grid, insufficient renewable energy generation, or grid failures, the energy storage system releases the stored electrical energy and converts it into AC power through inverters and other equipment, delivering it to the grid or supplying power to local loads to meet electricity demand, playing a role in peak shaving, valley filling, and improving power supply reliability.
3.Function
Peak shaving and valley filling: Charging during low electricity consumption periods and discharging during high electricity consumption periods to balance grid load, improve grid operation efficiency, and reduce grid construction costs.
Renewable energy consumption: storing excess electricity generated by renewable energy, reducing wind and solar power curtailment, improving the utilization rate of renewable energy, and promoting the large-scale application of renewable energy.
Improving power quality: Smooth the power fluctuations of renewable energy generation, reduce voltage fluctuations, frequency deviations, and harmonics, improve power quality, and ensure the normal operation of power equipment.
Emergency backup: In case of power grid failure or outage, it serves as a backup power source to provide temporary power support for important loads, ensuring the electricity needs of critical facilities and users.
Participate in power grid auxiliary services: can provide power grid auxiliary services such as frequency regulation, voltage regulation, reactive power compensation, etc., enhance the stability and reliability of the power grid, and improve the operational performance of the power grid.
4.Application
Distributed power generation projects, such as distributed solar power stations, small wind farms, etc., can improve the stability and reliability of power generation by configuring grid connected energy storage systems, and achieve surplus electricity storage and flexible utilization.
Industrial and commercial users: factories, shopping malls, office buildings, etc. can install grid connected energy storage systems to utilize the peak valley electricity price difference, charge and discharge during valley periods, reduce electricity costs, and serve as backup power sources to ensure the power supply of important equipment.
Grid side: Grid operators can construct large-scale grid connected energy storage power stations for peak shaving, frequency regulation, voltage regulation, and emergency backup of the grid, improving the overall performance and power supply quality of the grid.
Microgrid: In microgrids, grid connected energy storage systems are an important component that can achieve balance between power sources and loads within the microgrid, ensuring stable operation of the microgrid. At the same time, they can interact with the large grid to achieve optimized energy configuration.