GIC occurrences and GIC test for 400 kV system transformer

Lahtinen, Matti; Elovaara, Jarmo

doi:10.1109/61.997938

Cited by 84 publications

(69 citation statements)

References 6 publications

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“…The impact of quasi-dc GIC, for example, on power system transformers, depends on the magnitude and duration of the GIC and on the design, loading and set-up of the system (e.g. Kappenman and Albertson, 1990;Lahtinen and Elovaara, 2002). It follows that no general "rule of thumb" on GIC magnitudes can be easily assigned.…”

Section: Drivers Of Large Gic During the 6-7 April 2000 Geomagnetic Smentioning

confidence: 99%

April 2000 geomagnetic storm: ionospheric drivers of large geomagnetically induced currents

et al. 2003

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Abstract. Geomagnetically induced currents (GIC) flowing in technological systems on the ground are a direct manifestation of space weather. Due to the proximity of very dynamic ionospheric current systems, GIC are of special interest at high latitudes, where they have been known to cause problems, for example, for normal operation of power transmission systems and buried pipelines. The basic physics underlying GIC, i.e. the magnetosphere -ionosphere interaction and electromagnetic induction in the ground, is already quite well known. However, no detailed study of the drivers of GIC has been carried out and little is known about the relative importance of different types of ionospheric current systems in terms of large GIC. In this study, the geomagnetic storm of 6-7 April 2000 is investigated. During this event, large GIC were measured in technological systems, both in Finland and in Great Britain. Therefore, this provides a basis for a detailed GIC study over a relatively large regional scale. By using GIC data and corresponding geomagnetic data from north European magnetometer networks, the ionospheric drivers of large GIC during the event were identified and analysed. Although most of the peak GIC during the storm were clearly related to substorm intensifications, there were no common characteristics discernible in substorm behaviour that could be associated with all the GIC peaks. For example, both very localized ionospheric currents structures, as well as relatively large-scale propagating structures were observed during the peaks in GIC. Only during the storm sudden commencement at the beginning of the event were large-scale GIC evident across northern Europe with coherent behaviour. The typical duration of peaks in GIC was also quite short, varying between 2-15 min.

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Section: Drivers Of Large Gic During the 6-7 April 2000 Geomagnetic Smentioning

confidence: 99%

April 2000 geomagnetic storm: ionospheric drivers of large geomagnetically induced currents

et al. 2003

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“…In the case of technological systems, the term geomagnetically induced current (GIC) is used. GICs are of practical importance due to possibly harmful effects (Bolduc, 2002;Gummow, 2002;Kap-Correspondence to: A. Viljanen (ari.viljanen@fmi.fi) penman, 1996; Lahtinen and Elovaara, 2002;Lesher et al, 1994;Molinski, 2002;Osella et al, 1998;Pirjola et al, 2002). Only few really severe GIC disturbances have occurred, but developing methods for calculating the geoelectric field is relevant as basic research, too: a successful modelling of GIC requires a detailed knowledge of ionospheric currents and of the Earth's conductivity, and provides a comprehensive test for geospace models.…”

Section: Introductionmentioning

confidence: 99%

Fast computation of the geoelectric field using the method of elementary current systems and planar Earth models

Viljanen¹,

Pulkkinen²,

Amm³

et al. 2004

Ann. Geophys.

105

106

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Abstract. The method of spherical elementary current systems provides an accurate modelling of the horizontal component of the geomagnetic variation field. The interpolated magnetic field is used as input to calculate the horizontal geoelectric field. We use planar layered (1-D) models of the Earth's conductivity, and assume that the electric field is related to the local magnetic field by the plane wave surface impedance. There are locations in which the conductivity structure can be approximated by a 1-D model, as demonstrated with the measurements of the Baltic Electromagnetic Array Research project. To calculate geomagnetically induced currents (GIC), we need the spatially integrated electric field typically in a length scale of 100 km. We show that then the spatial variation of the electric field can be neglected if we use the measured or interpolated magnetic field at the site of interest. In other words, even the simple plane wave model is fairly accurate for GIC purposes. Investigating GIC in the Finnish high-voltage power system and in the natural gas pipeline, we find a good agreement between modelled and measured values, with relative errors less than 30% for large GIC values.

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“…Lahtinen and Elovaara, 2002). How can transformers be tested or certified for compliance with specifications that are intended to reduce damage by GICs?…”

Section: Ten Things We Don't Know About the Gic Risk To Power Gridsmentioning

confidence: 99%

Present day challenges in understanding the geomagnetic hazard to national power grids

Thomson

Gaunt

Cilliers³

et al. 2010

Advances in Space Research

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Power grids and pipeline networks at all latitudes are known to be at risk from the natural hazard of geomagnetically induced currents. At a recent workshop in South Africa, UK and South African scientists and engineers discussed the current understanding of this hazard, as it affects major power systems in Europe and Africa. They also summarised, to better inform the public and industry, what can be said with some certainty about the hazard and what research is yet required to develop useful tools for geomagnetic hazard mitigation.

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GIC occurrences and GIC test for 400 kV system transformer

Cited by 84 publications

References 6 publications

April 2000 geomagnetic storm: ionospheric drivers of large geomagnetically induced currents

April 2000 geomagnetic storm: ionospheric drivers of large geomagnetically induced currents

Fast computation of the geoelectric field using the method of elementary current systems and planar Earth models

Present day challenges in understanding the geomagnetic hazard to national power grids

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