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Impact of volcanic ash from Cotopaxi-2015 and Tungurahua-2016 eruptions on the dielectric characteristics of suspension insulators, Ecuador

Authors :
Juan Ramírez
Francisco J. Vasconez
Alex López
Fausto Valencia
Franklin Quilumba
Anais Vásconez Müller
Silvana Hidalgo
Benjamin Bernard
Source :
Journal of Applied Volcanology, Vol 11, Iss 1, Pp 1-21 (2022)
Publication Year :
2022
Publisher :
BMC, 2022.

Abstract

Abstract In Ecuador, a country with several active volcanoes and with four eruptions in the last decade in the continental arc, it is very likely that high-voltage transmission lines cross volcanic hazard zones on their routes. Here, we quantify the impact of fresh volcanic ash from the hydromagmatic Cotopaxi-2015 and the magmatic Tungurahua-2016 eruptions on the dielectric characteristics of ANSI 52–3 suspension insulators made of porcelain and glass, under moist conditions. The experiments include two methodologies to measure the performance of the insulators in real-time: the minimum insulator flashover voltage (FOVmin) and the dielectric loss factor angle. Both allow quantifying i) the critical voltage that the insulators can withstand prior to flashover occurrence and, ii) the strong fluctuating behavior that the insulators undergo in an ashy environment. Based on six contamination scenarios, we found that there is a higher chance of flashover if the insulators are completely blanketed (top and bottom) even with a fine ash layer (1 mm), than if they are covered just at the top. Our results further show that the ash of Cotopaxi-2015 eruption has a higher chance of leading to insulator failure because of its higher conductivity (i.e. higher leachate content) than that of Tungurahua-2016. Additionally, we identify two critical voltages prior to electrical flashover on the insulators of 28.25 kV and 17.01 kV for the 230 kV and 138 kV Ecuadorian transmission lines, respectively. Finally, we present a simple impact evaluation for the main Ecuadorian transmission lines based on the outcomes of this research and the official volcanic hazard maps for Cotopaxi and Tungurahua volcanoes.

Details

Language :
English
ISSN :
21915040
Volume :
11
Issue :
1
Database :
Directory of Open Access Journals
Journal :
Journal of Applied Volcanology
Publication Type :
Academic Journal
Accession number :
edsdoj.127246f5e5f74b568f2defb75d9a2b2f
Document Type :
article
Full Text :
https://doi.org/10.1186/s13617-022-00117-y