Research on the application of energy storage converter in bidirectional energy flow between energy storage system and power grid
Publish Time: 2024-06-17
With the widespread application of renewable energy and the rapid development of smart grids, energy storage systems, as an important part of the power grid, have great significance for maintaining the balance and efficient operation of the power grid due to their stability and reliability. As the core equipment of the energy storage system, the energy storage converter (PCS, Power Conversion System) can realize the bidirectional flow of electric energy between the energy storage system and the power grid, which plays an important role in improving the energy utilization efficiency of the power grid, optimizing energy configuration, and enhancing the stability of the power grid.Working principle of energy storage converterBased on power electronics technology and modern control theory, the energy storage converter realizes the bidirectional conversion of direct current (DC) and alternating current (AC) electric energy through the switching action of high-efficiency power semiconductor devices (such as IGBT, MOSFET). During the charging process, the energy storage converter converts the AC power in the power grid into DC power to charge the energy storage system; during the discharging process, the energy storage converter converts the DC power in the energy storage system into AC power to supply the power grid or load.Application of energy storage converter in bidirectional flow of electric energy between energy storage system and power gridEnergy conversionThe energy storage converter can realize the bidirectional conversion of electric energy between the energy storage system and the power grid. In charging mode, the energy storage converter converts the AC power in the grid into DC power to charge the energy storage system; in discharging mode, the energy storage converter converts the DC power in the energy storage system into AC power to supply the grid or load. This bidirectional conversion function enables the energy storage system to flexibly respond to the needs of the grid and achieve optimal scheduling and configuration of electric energy.Charging and discharging managementThe energy storage converter receives background control instructions through the built-in controller, and controls the converter to charge or discharge the battery according to the sign and size of the power instruction. This management method helps the grid to provide additional power during peak demand or store excess power during low demand, thereby achieving a balance between supply and demand of the grid.Improved grid stabilityThe energy storage converter can quickly respond to fluctuations in grid frequency, voltage and other parameters, balance the grid load by adjusting the charge and discharge rate of the energy storage device, and maintain the frequency of the grid stable. In addition, the energy storage converter can also control the phase of the current to achieve reactive power control, thereby improving the power factor of the grid, reducing energy loss, and optimizing the power quality of the grid.Working mode switchingThe energy storage converter has two working modes: grid-connected and off-grid. In grid-connected mode, the energy storage converter realizes bidirectional energy conversion between the energy storage battery and the grid; in off-grid mode, the energy storage converter can provide AC power that meets the power quality requirements of the grid to the local partial load. This flexible working mode switching capability enables the energy storage system to adapt to different application scenarios and needs.As the core equipment of the energy storage system, the energy storage converter realizes the bidirectional flow of electric energy between the energy storage system and the grid, which is of great significance for improving the energy utilization efficiency of the grid, optimizing energy configuration, and enhancing the stability of the grid. In the future, with the further development of renewable energy and smart grids, energy storage converters will play a more important role.
