Resilience Assessment of Overhead Power Distribution Systems under Strong Winds for Hardening Prioritization

Abstract

During extreme weather and other emergency conditions, the safety and resilience of the overhead power distribution system is essential for communities. Quick detection of damaged poles and wires as well as quick recovery from outages in a limited time period requires a better understanding of the structural performance and the interactions of the structures with the surrounding environmental conditions, such as wind and vegetation conditions. In the present study, the resilience of the pole-wire system was analyzed after establishing a system analysis framework for structural reliability and hardening/inspection priority analysis. Following a brief introduction of the resilience concept, the inputs and outputs of the system are introduced along with the automatic modeling scheme for the pole-wire system. For the purpose of demonstration, a typical three-span pole-wire system is established. Based on Monte Carlo simulations, fragility assessment of the pole-wire system is performed for two cases: an extreme wind load case and a typical tree-branch weight load case. Finally, a realistic single-circuit overhead distribution system in a community is established for discussion. The system reliability is evaluated to identify the critical pole locations and critical wind direction. On the basis of the analysis results, hardening prioritization options are suggested and discussed.