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Calculation of voltages in electric power transmission lines during historic geomagnetic storms: An investigation using realistic earth impedances

February 27, 2018

Commonly, one-dimensional (1-D) Earth impedances have been used to calculate the voltages induced across electric power transmission lines during geomagnetic storms under the assumption that much of the three-dimensional structure of the Earth gets smoothed when integrating along power transmission lines. We calculate the voltage across power transmission lines in the mid-Atlantic region with both regional 1-D impedances and 64 empirical 3-D impedances obtained from a magnetotelluric survey. The use of 3-D impedances produces substantially more spatial variance in the calculated voltages, with the voltages being more than an order of magnitude different, both higher and lower, than the voltages calculated utilizing regional 1-D impedances. During the March 1989 geomagnetic storm 62 transmission lines exceed 100 V when utilizing empirical 3-D impedances, whereas 16 transmission lines exceed 100 V when utilizing regional 1-D impedances. This demonstrates the importance of using realistic impedances to understand and quantify the impact that a geomagnetic storm has on power grids.

Publication Year 2018
Title Calculation of voltages in electric power transmission lines during historic geomagnetic storms: An investigation using realistic earth impedances
DOI 10.1002/2017SW001779
Authors Greg M. Lucas, Jeffrey J. Love, Anna Kelbert
Publication Type Article
Publication Subtype Journal Article
Series Title Space Weather
Index ID 70195684
Record Source USGS Publications Warehouse
USGS Organization Geologic Hazards Science Center
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