Vulnerability assessment of the power grid against progressing wildfires. (April 2015)

• Record Type: Journal Article
• Authors: Choobineh, Moein; Ansari, Bananeh; Mohagheghi, Salman
• Is Part Of: Fire safety journal. Volume 73(2015:Apr.)
• Page Start: 20
• Page End: 28
• Publication Date: 2015-04
• Subjects: Conductor ampacity -- Dynamic thermal rating -- Natural disaster -- Power generation dispatch -- Power grid -- Wildfires; Fire prevention -- Periodicals; Incendies -- Prévention -- Recherche -- Périodiques; Fire prevention -- Research; Periodicals; 628.92205
• DOI: 10.1016/j.firesaf.2015.02.006
• Languages: English
• ISSNs: 0379-7112

Abstract

Abstract: Wildfires are common in many forest and grassland ecosystems. Power transmission lines are vulnerable to wildfires in their vicinity, mainly due to increased conductor temperatures as a result of heat released by the fire. This may damage the conductor and lead to violation of safety clearances between conductor and ground. To address the situation, a power system operator may dynamically alter the ratings of the lines in the affected areas to reduce the current flowing through them, thereby assisting with conductor cooling. A unified model is proposed here that allows for dynamically changing the thermal ratings of conductors in the vicinity of a wildfire. The proposed model incorporates the radiative and convective heat released due to a progressing wildfire into the conductor thermal rating calculation in order to derive the updated conductor rating. Case studies are presented to show the effects of a progressing wildfire on a power system. It is shown that dynamically changing the ratings of power lines changes the flow of power through the network, moving the system towards a sub-optimal operating point. Under heavy loading conditions, this may even lead to imbalance between load and generation, therefore forcing involuntary load shedding to avoid system collapse. Highlights: Wildfires affect the available capacity of transmission lines in their vicinity. A model is proposed to calculate dynamic rating of lines exposed to wildfire. We modify line rating based on the heat released by a progressing wildfire. If line rating is not modified, heat may result in line damage and safety issues. Updated line rating leads to suboptimal operating point for the power system.