Resilience based Criticality Analysis for Seismic Performance Assessment of Underground Cables

The concept of resilience in power systems has gained focused attention due to increasing outages, including large-scale blackouts, attributed directly or indirectly due to extreme weather and natural geo-physical triggered events. The resilience of electricity infrastructure ground assets and power system equipment can be improved by strengthening the foundations or re-engineering the vulnerable impact spots of equipment. However, understanding the criticality and thereby assessing resilience of underground cables is challenging due to the underground dynamics and the infrastructure spanning across a large geographical area. The cables go through different terrains and depths and the effects of earthquakes vary on these cables depending upon the magnitude. To address this problem, this piece of research explores the potential use of geospatial information software's to map underground cables to study the performance of underground cables by evaluating the repair rates and developing fragility curves for underground cables damaged based on utility data during an earthquake event. Based on the observed case-study, a resilience-based criticality framework is proposed for underground cables. This helps provide actionable and accepted metrics, particularly for short term and long-term resilience of underground cables in a distribution network.