Improved modeling of geomagnetically induced currents in the South African power network
Improved modeling of geomagnetically induced currents in the South African power network
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DOI：
10.1029/2008sw000408
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发表时间：
2008-11
期刊：
影响因子：
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通讯作者：
C. Ngwira;A. Pulkkinen;L. McKinnell;P. Cilliers
中科院分区：
文献类型：
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作者：
C. Ngwira;A. Pulkkinen;L. McKinnell;P. Cilliers
已经证明，不利的空间天气造成的地磁感应电流会对中纬度地区的电力变压器造成损害。由于南部非洲电网的电力线较长，人们越来越担心可能产生的GIC效应。先前在南非对与GIC相关的电场进行建模的努力使用了统一的地面电导率模型。为了改进GIC的建模，GIC数据与赫马努斯地磁观测站的地磁场数据一起使用，以获得多层地面电导率结构。该方法需要定义网络系数，然后将其用于后续计算。研究表明，使用新的网络系数和多层地面电导率模型计算的GIC提高了GIC建模的准确性。GIC统计数据是根据1996年至2006年赫马努斯地磁场的记录、新的网络系数和地面电导率模型得出的。地电场采用平面波法模拟。
Geomagnetically induced currents (GICs), resulting from adverse space weather, have been demonstrated to cause damage to power transformers in the midlatitudes. There is growing concern over possible GIC effects in the Southern African network because of its long power lines. Previous efforts to model the electric field associated with GICs in South Africa have used a uniform ground conductivity model. In an effort to improve the modeling of GICs, GIC data together with the Hermanus Magnetic Observatory geomagnetic field data were used in order to obtain a multilayered ground conductivity structure. The method requires a definition of the network coefficients, which are then used in subsequent calculations. This study shows that GIC computed using the new network coefficients and the multilayered ground conductivity model improves the accuracy of GIC modeling. GIC statistics are then derived on the basis of the recordings of the geomagnetic field from 1996 to 2006 at Hermanus, the new network coefficients, and ground conductivity model. The geoelectric field was modeled using the plane wave method.