Reliability and Safety
Investigation into Storm Hardening the Electric Transmission System for Puget Sound Energy
The Puget Sound Energy (PSE) service area experienced winds ranging from gale force to the equivalent
of a category two hurricane over December 14-15, 2006. With soils saturated from previous heavy rains,
tens of thousands of trees uprooted, falling onto power lines and substations. More than 40% of PSE’s
transmission lines were knocked out of service...
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Trees and Reliability
Tree-conductor conflicts are a leading cause of unplanned power interruptions, causing both momentary and long-duration outages. Trees impact power-delivery...
Risk Assessment on Distribution Systems: What's the Point?
An analysis of hazard trees that identifies common barriers to effective management; actions necessary to make substantial hazard tree identification improvements; the reliability improvement achieved, and the limits of the wind loading range over which the hazard tree program benefits accrue.
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Tree Root Causes
A detailed look at tree-related service interruptions that provides insight into both the nature of the challenge and where reliability improvements might be made. Consistent with other utility experience, only 45% of tree and branch failures have an indicator of increased failure risk.
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Trees and Their Impact on Electric Reliability During and Following Tropical Storm Isabel
With Isabel, rainfall was less than expected and wind speeds were below those normally associated with significant tree failure. Despite this situation, tree failures and associated utility outages were massive.
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Tree Risk Assessment and Reliability
A good look at the state of knowledge regarding trees and electric service interruptions with some well-grounded data. Presents a strong argument for post-interruption data collection as a guide to effective outage mitigation.
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Phasing in Covered Wire
The Pacific Northwest boasts many tall trees. Oregon in particular is known for its Douglas fir forests. When combined with wind, snow and ice, these...
Florida Electric Utility Infrastructure Storm Hardening Workshops
Florida Electric Utility Infrastructure Storm Hardening Workshops in the aftermath of the 2004 and 2005 hurricane seasons.
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Cost-Benefit Analysis of the Deployment of Utility Infrastructure Upgrades and Storm Hardening Programs
An examination of hardening possibilities for Texas utilities in the aftermath of Hurricane Ike.
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Utility Vegetation Management Final Report
Final Report on the August 14, 2003 Blackout in the United States and Canada
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