Electric grid resilience: The effects of conductor coverings, enhanced tree trimming, and line characteristics on tree-related power outages

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Tree damage is a major cause of storm power outages in forested regions of the world which results in substantial economic losses each year. Utilities must understand the effectiveness of resilience programs to make the best use of limited resources. Our study evaluated the effectiveness of covered conductors and enhanced tree trimming (ETT) in reducing tree-related outages during storms for an electric overhead distribution system. Our study area was the Eversource Energy service area in Connecticut which has heavy forest cover coinciding with areas of high population density. We controlled for the effects of confounding factors including weather, power line phase, and tree canopy cover. Covered conductors and ETT were similarly effective in reducing power outages with median rate reductions of 0.19 - 0.29 outages/km/year. When used in combination, covered conductors with ETT had a significant additive effect with median reductions of 0.29 – 0.33 outages/km/year compared to bare conductors with no ETT. Multiphase power lines had median outage rates that were 0.17 – 0.37 outages/km/year lower than outage rates for single-phase power lines. Our findings will help utilities select and justify their choices of resilience strategies and more accurately predict outage locations in advance of approaching storms.

Publication Title, e.g., Journal

Electric Power Systems Research