Seismic performance assessment of electric power systems subjected to spatially correlated earthquake excitations

Abstract

Electric power systems play a critical role in assuring modern society’s functionalities. Earthquakes are one of the most destructive natural hazards that affect the serviceability of electricity transmission systems. The earthquake excitations applied to each component of a power system (e.g. plants, substations and transmission lines) are spatially correlated by nature due to common causes. Yet, limited attention has been paid to the impact of this spatial correlation on the power grid seismic performance. This article presents an approach for estimating the seismic performance of large-scale electric power systems subjected to spatially correlated earthquake ground motions. The network flow theory is used to model the power flow allocation over the grid components, and a stochastic ground motion model is employed to represent the spatial characteristics of earthquake excitations. The proposed method is illustrated through the seismic performance assessment of the national power grid of Italy. The overall vulnerability is measured and evaluated through a proposed metric, and the critical components of the grid system are identified. The impact of spatial correlation of earthquake ground motion on the grid system’s post-hazard performance is also investigated.