Probability-based seismic resilience assessment method for substation systems

Abstract

Electricity has substantial effects on rescue and relief responses after strong earthquakes. Substations are essential components of electric power networks, and their seismic performance has recently attracted the attention of academia and industry, in particular, the recovery capacity from external events. This capacity is referred to as seismic resilience, which is defined as the ability of a system to resist, recover from, and adapt to an earthquake impact. It is quantified as the change in functionality over time. However, it is challenging to quantify the optimum recovery process dynamically due to interrelations between components. In this paper, a new probability-based method is proposed to assess the seismic resilience of complex systems, such as substations. A case study is performed on a typical 220 kV substation in China, and the seismic resilience of the system is investigated focussing on three important issues: (1) definition of system functionality; (2) a system model that considers the interrelations among the components; (3) recovery strategies to restore system functionality. The resilience index of the system with a functionality prioritisation recovery strategy is two to three times higher than that of a pre-determined one at the maximum considered earthquake.