Research on modeling and grid connection stability of large-scale cluster energy storage power station based on digital mirroring

Abstract

With the large-scale integration of renewable energy into the grid, its randomness and intermittent characteristics will adversely affect the voltage, frequency, etc. of the new power system, and even cause partial system collapse. However, the above problems can be solved by configuring large-scale clustered energy storage in the new power system. This paper proposes the structure and technical points of the digital mirroring system of large-scale clustered energy storage power station, and conducts mathematical modeling for the lithium-ion battery system and grid-connected system of Power Conversion System (PCS for short) of large-scale clustered lithium-ion battery energy storage power station. Based on this, This paper proposes a control strategy that introduces virtual resistance, establishes a Norton equivalent circuit with multiple PCSs operating in parallel, and then analyzes the stability of multiple PCSs in parallel operation, and gives the value range and influence parameters of the virtual resistance when the system is operating stably. Finally, experiments and simulation analysis verify the rationality and applicability of the conclusions and methods of this paper.

Keywords

• Digital mirroring
• Modeling of energy storage power station
• Control strategy
• Grid-connected stability