Analyzing the inertia of power grid systems comprising diverse conventional and renewable energy sources

The global pursuit of low-carbon technologies has led to the rapid development of renewable energy sources (RES), such as wind and solar power. The large-scale integration of RES into power grid systems can change the characteristics and forms of the system inertia. RES-heavy power systems exhibit lower inertia, compromising their frequency stability and rendering traditional inertia response mechanisms and analysis methods insufficient. This review compares the different inertias in traditional and future RES-heavy power systems, details the inertia response mechanisms of various types of devices, identifies deficiencies in the traditional inertia index when quantifying the inertia response capabilities of the equipment, and illustrates the necessity of exploring a generalized inertia index suitable for such systems. Furthermore, the influence mechanism of system inertia on frequency stability is analyzed, and the action mechanism and response time sequence of various types of devices in the system inertia response are described. The challenges in applying the traditional frequency stability analysis method to future RES-heavy power systems are also identified. This review can serve as a guide for developing power grid control systems and analysis methods to accommodate the increasing application of RES.