Preliminary Research on the Representation Form of Spatial-temporal Distribution Characteristics of Power System Inertia Under a Major Disturbance

Large-scale grid integration of renewable energy sources has led to a continuous reduction in the inertia of the power system, and the spatial distribution characteristics of the system inertia resources are becoming increasingly significant. Most studies on the spatial-temporal distribution of system inertia (SDSI) have focused on inertia estimation. Meanwhile, the representation of the concept of system inertia is not unified and lack the in-depth analysis of its characteristics and the systematic sorting and analysis of related concepts. This paper attempts to explore the representation form of the SDSI characteristics under a major disturbance. The concept of system nodal inertia is proposed and its characteristic description parameters are given. Based on the three-machine equivalent system frequency response (TM-SFR) model, the analytical formula of the nodal inertia is derived. The WSCC 9 bus system is used to verify the analysis and judgment of the SDSI characteristics, which can be characterized comprehensively and normally by the proposed representation form.