In this paper, we investigate the influence of the locations of inverter-based resources (IBRs) on the synchronization performance of power networks. We propose two indexes to measure the distribution of inertia in power networks, considering the distribution of control parameters and the topological factors jointly. The first index is the inertia clustering coefficient, which measures how densely the neighbors of each node are connected in a power network. The second index is the inertia centrality coefficient, which captures whether the distribution of inertia in a power network is centralized or peripheral. We characterize synchronous generators (SGs), grid-following inverters (GFLs), and grid-forming inverters (GFMs) by their damping and inertial properties. We evaluate the synchronization performance of the system after disturbances by adopting the settling time and hertz-sec metric. Both the frequency response and the trajectories of eigenvalues show that the location of IBRs has a significant impact on the synchronization performance of the system. Monte Carlo simulations are conducted on two test networks, the results of the IEEE 30-, 57-, and 118-bus systems demonstrate a strong correlation between synchronization performance and the two inertia distribution indexes.
I took the risk of applying complex network analysis to the synchronization performance of inverter-based resources. I made several simplifications to highlight the key issues. 🦄✨**