Modeling Geomagnetically Induced Currents in Australian Power Networks Using Different Conductivity Models
Modeling Geomagnetically Induced Currents in Australian Power Networks Using Different Conductivity Models
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DOI：
10.1029/2018sw002047
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发表时间：
2019-05
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通讯作者：
R. Marshall;Liejun Wang;G. Paskos;G. Olivares-Pulido;T. V. D. Walt;C. Ong;D. Mikkelsen;G. Hesse;B. McMahon;E. V. Wyk;G. Ivanovich;D. Spoor;C. Taylor;Akimasa Yoshikawa
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作者：
R. Marshall;Liejun Wang;G. Paskos;G. Olivares-Pulido;T. V. D. Walt;C. Ong;D. Mikkelsen;G. Hesse;B. McMahon;E. V. Wyk;G. Ivanovich;D. Spoor;C. Taylor;Akimasa Yoshikawa
空间天气在电力网络中表现为通过高压变压器的接地中性点流入和流出电力系统的准直流电流，称为地磁感应电流。本文提出了一种比较的建模地磁感应电流，确定使用地电场来自四个不同的阻抗模型，采用不同的导电性结构，与地磁感应电流测量从澳大利亚东部各州的电力系统内。四种不同的阻抗模型是均匀电导率模型（UC）、一维n层电导率模型（NU和NW）和澳大利亚地区的三维电导率模型（3DM），从中计算大地电磁阻抗张量。模拟的3DM张量显示出良好的协议与测得的大地电磁张量最近发布的数据从澳大利亚岩石圈结构大地电磁项目。四个不同的阻抗模型应用到一个网络模型的四个地磁风暴的太阳活动周期24，并与观测数据从8个不同的位置在网络内进行比较。使用几个统计性能参数的模型进行评估。对于相关值大于0.8和幅度比例因子小于2，3DM模型比简单的电导率模型表现更好。当考虑模型性能参数P时，3DM模型的个体P值最高。根据地下地质结构和电网电气参数讨论了结果的意义。
Space weather manifests in power networks as quasi‐DC currents flowing in and out of the power system through the grounded neutrals of high‐voltage transformers, referred to as geomagnetically induced currents. This paper presents a comparison of modeled geomagnetically induced currents, determined using geoelectric fields derived from four different impedance models employing different conductivity structures, with geomagnetically induced current measurements from within the power system of the eastern states of Australia. The four different impedance models are a uniform conductivity model (UC), one‐dimensional n‐layered conductivity models (NU and NW), and a three‐dimensional conductivity model of the Australian region (3DM) from which magnetotelluric impedance tensors are calculated. The modeled 3DM tensors show good agreement with measured magnetotelluric tensors obtained from recently released data from the Australian Lithospheric Architecture Magnetotelluric Project. The four different impedance models are applied to a network model for four geomagnetic storms of solar cycle 24 and compared with observations from up to eight different locations within the network. The models are assessed using several statistical performance parameters. For correlation values greater than 0.8 and amplitude scale factors less than 2, the 3DM model performs better than the simpler conductivity models. When considering the model performance parameter, P, the highest individual P value was for the 3DM model. The implications of the results are discussed in terms of the underlying geological structures and the power network electrical parameters.