Research on improving transient voltagestability of energy storage system

Abstract

The transient overvoltage and voltage sags caused by DC blocking in HVDC transmission systems cause great harm to the stable operation of transmission equipment and power system. This paper analyzes the AC/DC equivalent circuit model of battery energy storage system, and deduces the calculation method of the transient voltage of the converter bus at the rectifier side when the remaining reactive power compensation capacity of the converter station is known. According to the results of regulating the transient voltage of the bus at the dc latched rear end of the energy storage station, the calculation method of reactive power of charge and discharge of the energy storage station is further derived. On this basis, the reactive power control method of regulating the transient voltage of the bus at rectifier side of the energy storage station is given. The power system comprehensive simulation program based on IEEE-39 node system is used to conduct simulation analysis to verify the correctness and effectiveness of the theoretical analysis, and the conclusion is drawn that the energy storage power station has a good regulating effect on the voltage fluctuation caused by DC blocking after being connected to the grid.