Probabilistic framework for assessing the vulnerability of power distribution infrastructures under extreme wind conditions

Abstract

Utility poles would collapse by their structural instability as well as time-dependent material deterioration. Particularly, the moment carrying capacity of leaning poles would be dramatically reduced during extreme wind events. In this paper, we regard leaning poles as warning signs of potential failures that can affect the power distribution network performance and estimate the failure probability of leaning poles. To analyze the moment behavior of leaning poles, we propose a new probabilistic framework for computing three types of loads by wind pressure, overturning force, and conductor tension. A set of fragility curves of utility poles with given ages and leaning angles are presented to assess the impact of leaning on the probability of failure. The proposed analytics are tested through a case study on the parts of the power distribution network in Houston, TX. By examining the progress of failure in the network, this method enables to analyze potentially vulnerable utility poles that are likely to threaten the power distribution system reliability under varying wind speed. Thus, this research has the potential to support risk-informed decision-making for power distribution infrastructure systems and ultimately enhance the urban community resilience to blackouts caused by the power distribution system disruption in extreme weather.