Geomagnetically induced currents in Norway: the northernmost high-voltage power grid in the world
Geomagnetically induced currents in Norway: the northernmost high-voltage power grid in the world
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挪威的地磁感应电流：世界上最北的高压电网
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
T. Ohnstad
中科院分区：
文献类型：
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作者：
M. Myllys;A. Viljanen;O. Rui;T. Ohnstad
我们推导了地磁活动的综合统计数据，用于评估挪威高压电网中地磁感应电流（GIC）的发生。统计研究基于1994-2011年的地磁记录，从中可以对地电场进行建模，并将其应用于电网的直流描述以估计GIC。挪威电网中最大的GIC（高达100 a）最有可能发生在其南部地区。这主要是因为电网的结构有利于南方的大型GIC。磁场在北方的平均变化速度最快，但在极端的地磁风暴期间，它们在南方也达到了类似的值。南方的地面电导率也较小，这进一步增加了那里的电场。除了1994-2011年的结果之外，我们还通过外推统计数据对地电场进行了每100年一次的事件的初步估计。发现1994-2011年最大地电场值是最大值的2倍。这个值实际上是在1982年7月13日至14日达到的。
We have derived comprehensive statistics of geomagnetic activity for assessing the occurrence of geomagnetically induced currents (GIC) in the Norwegian high-voltage power grid. The statistical study is based on geomagnetic recordings in 1994–2011 from which the geoelectric field can be modelled and applied to a DC description of the power grid to estimate GIC. The largest GIC up to a few 100 A in the Norwegian grid occur most likely in its southern parts. This follows primarily from the structure of the grid favouring large GIC in the south. The magnetic field has its most rapid variations on the average in the north, but during extreme geomagnetic storms they reach comparable values in the south too. The ground conductivity has also smaller values in the south, which further increases the electric field there. Additionally to results in 1994–2011, we performed a preliminary estimation of a once per 100 year event for geoelectric field by extrapolating the statistics. We found that the largest geoelectric field value would be twice the maximum in 1994–2011. Such value was actually reached on 13–14 July 1982.