Age-dependent resilience assessment and quantification of distribution systems under extreme weather events

Abstract

The impact of extreme weather events on power system resilience can be seen in historical electrical disruptions. Due to the increasing intensity and frequency of extreme weather events following global warming and climate change, a greater focus is required to design power systems with high resilience and low cost through assessing and quantifying power system resilience. In this way, we propose a transparent methodology and a set of metrics to quantify the resilience of distribution systems subjected to hurricanes. This methodology includes a probabilistic and detailed approach to modelling the failure probability of overhead lines and the restoration time of damaged lines. Moreover, the fragility analysis of the power system infrastructure is considered age-dependent, and the system’s resilience by considering different lifetimes is assessed. The time-dependent resilience assessment constitutes an essential component in risk-informed decision-making for resilience enhancement strategies in the future. Specifically, this paper provides two resilience curve-based metrics: vulnerability rate and restoration rate. The first metric indicates the power system’s ability to resist extreme events, and the second indicates its ability to bounce back to normal performance. Simulations are performed on the IEEE 69-bus distribution test system to validate the suggested methodologies. The results indicate the capability of the proposed methodology and metrics to precisely assess and quantify the power system resilience. A significant correlation between the age of power distribution systems and the system’s resilience can be seen. These findings can support decision-making concerning system management and plans such as expansion planning and resource allocation.