Analysis of power system inertial demand considering frequency security and stability constraints

Under the background of new energy large-scale grid integration, the inertia of the power system gradually decreases, which brings great challenges to the operation of the power grid. The unclear demand of inertia will restrict the carrying capacity and frequency stability of the power system, and there is an urgent need to find an inertial demand analysis method considering the frequency security and stability constraints. This paper begins by outlining the source and definition of inertia. According to the dynamic frequency response characteristics of the power system, it finds the relationship between system inertia and frequency. Then, based on the relevant frequency stability indicators, a method is proposed to determine the critical inertia that takes into account the rate of change of frequency (RoCoF) and the deviation constraints of the frequency. Finally, an improved IEEE9 node example is built on the PSCAD/EMTDC platform to prove the reliability of the theory proposed in this paper.