Locational Dependence of Inertia’s Impacts on Critical Clearing Time

With the integration of renewable energy, system inertia may have a trend of decreasing in recent years, which increases the likelihood of transient instability. Inertia has impacts on voltage profiles and such impacts vary by location. After the system is subject to faults on buses or on transmission lines, bus voltages change differently as sum of inertia varies in sites that are either near or far away from violation locations. Critical clearing time (CCT) is a metric assessing condition of system stability. This paper displays how inertia changes affect CCT and how such impacts are location-dependent. An insightful preliminary study is carried out to reveal how inertia comes into play in bus voltage levels. Two case sets considering different oscillations are presented to verify inertia's locational impacts on CCT.