Methodology for Identifying Regional Inertia Issues in Future Power Grids

Regional inertia challenges can emerge in a large power system if high, local penetrations of renewable generation begin to create weakly connected, low inertia regions within the system. These regions may be exposed to large frequency deviations or rate of change of frequency (RoCoF) in the event of a large loss of infeed/outfeed in such a region. This paper presents a screening methodology that can identify potential regional inertia issues in a power system without using time domain simulations. This provides a basis for transmission planners to screen for potential weakly coupled regions of inertia and thereby take necessary actions for maintaining security in key vulnerable locations. The methodology identifies the regions in a system using spectral clustering and a suitable metric, and then assesses their vulnerability based on the size of the single largest infeed in each region. The focus is on creating a framework that can identify regional inertia issues in the system without the need for time-domain analysis.