Research on frequency regulation strategy of battery energy storage system supporting power system

Abstract

Due to the large-scale grid connection of new energy, the inertia of the power system has decreased, seriously affecting the frequency stability of the power grid, and there is an urgent need for effective frequency support technology. In response to the above issues, this article proposes a frequency control strategy for battery energy storage systems to support power systems. Firstly, establish a battery equivalent circuit model to simulate the dynamic and static performance as well as external characteristics of the battery; Secondly, two frequency modulation strategies, droop control and accelerated droop control, are used to control the active power emitted by the battery energy storage system. Finally, a four-machine two-zone system with a 25% proportion of wind power was built using MATLAB for simulation analysis in two scenarios: sudden reduction of wind power and rapid fluctuation of wind power. The results showed that the frequency modulation strategy proposed in this paper can effectively improve the lowest and stable point frequencies of the system, and can slow down the rate of frequency decline, thereby improving the frequency stability of the power grid.