Evaluation of power systems resilience to extreme weather events: a review of methods and assumptions

The requirement for a sustained supply of electricity intensifies during and in the aftermath of extreme events. In the past, events were considered extreme based on their extensive and devasting impacts and also because they were rare. However, recent studies report an increase in the frequency, intensity, and duration of weather-related power outages. Several studies have proposed approaches for evaluating and enhancing power system resilience. The generic approach entails characterizing weather threats, assessing the system components’ vulnerabilities, analyzing system response, evaluating baseline resilience, and assessing the effectiveness of resilience enhancement measures. This study is a review of the different assumptions and models employed in this multiphase analysis process. To demonstrate its utility, a brief use case has been provided to ascertain Great Britain’s transmission network’s resilience against a lightning strike. The findings demonstrate that network outturn during a threat can severely be influenced by internal systemic maloperations rather than the event’s intensity. This challenges the pervasive view of resilience assessment which mainly focuses on exogenous threats. Moreover, the study highlights threat characterization and vulnerability assessment phases as the main sources of uncertainties that can be moderated through the capture of relevant data aimed at developing holistic empirical fragility functions.