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TitleModelling natural electromagnetic interference in man-made conductors for space weather applications
AuthorTrichtchenko, L
SourceAnnals of Geophysics vol. 34, issue 4, 2016 p. 427-436, (Open Access)
Alt SeriesEarth Sciences Sector, Contribution Series 20160022
PublisherCopernicus GmbH
Mediapaper; on-line; digital
File formatpdf
Subjectsgeophysics; geomagnetism; geomagnetic fields; electromagnetic fields; energy; electric power; pipelines; conductivity; electromagnetic induction; transportation; paleomagnetism; modelling; space weather; infrastructure; power transmission; e m conductors; geomagnetically induced currents (GIC)
Illustrationsschematic diagrams; tables; graphs; cross-sections; plots
ProgramNorthern Canada Geohazards Project, Public Safety Geoscience
Released2016 04 14
AbstractPower transmission lines above the ground, cables and pipelines in the ground and under the sea, and in general all man-made long grounded conductors are exposed to the variations of the natural electromagnetic field. The resulting currents in the networks (commonly named geomagnetically induced currents, GIC), are produced by the conductive and/or inductive coupling and can compromise or even disrupt system operations and, in extreme cases, cause power blackouts, railway signalling misoperation, or interfere with pipeline corrosion protection systems. To properly model the GIC in order to mitigate their impacts it is necessary to know the frequency dependence of the response of these systems to the geomagnetic variations which naturally span a wide frequency range. For that, the general equations of the electromagnetic induction in a multi-layered infinitely long cylinder (representing cable, power line wire, rail or, pipeline) embedded in uniform media have been solved utilising methods widely used in geophysics. The derived electromagnetic fields and currents include the effects of the electromagnetic properties of each layer and of the different types of the surrounding media. This exact solution then has been used to examine the electromagnetic response of particular samples of long conducting structures to the external electromagnetic wave for a wide range of frequencies. Because the exact solution has rather complicated structure, the simple approximate analytical formulas have been proposed, analysed and compared with the results from the exact model. These approximate formulas show good coincidence in the frequency range spanning from geomagnetic storms (less than mHz) to pulsations (mHz to Hz) to atmospherics (kHz) and above, and can be recommended for use in the space weather applications.
Summary(Plain Language Summary, not published)
Space weather refers to the dynamic conditions on the Sun and in the space environment, in particular, in the near-Earth environment, that can affect critical infrastructure. NRCan operates the Canadian Space Weather Forecast Centre and conducts research into space weather effects on power systems, pipelines, radio communications and GNSS positioning to help Canadian industry understand and mitigate the effects of space weather. To help engineers understand how space weather can affect ground infrastructure, this paper provides derivation, analysis and validation of the frequency dependent approach to the modelling of geomagnetically induced currents.