Transformer-Level Modeling of Geomagnetically Induced Currents in New Zealand's South Island
Transformer-Level Modeling of Geomagnetically Induced Currents in New Zealand's South Island
复制标题
新西兰南岛地磁感应电流的变压器级建模
DOI：
10.1029/2018sw001814
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发表时间：
2018
期刊：
影响因子：
3.7
通讯作者：
Divett T
中科院分区：
文献类型：
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作者：
Divett T
在空间天气事件期间，地磁感应电流（GIC）可能会在高压输电网络中产生，从而损坏变电站内的单个变压器。一个常见的方法来建模的传输网络已经假设，每个变电站可以表示为一个单一的接地电阻。我们通过构建新西兰南岛输电网络的Transformer级网络表示来扩展该模型。我们用已知的直流电阻来表示网络中每个变电站的每个Transformer绕组。与基于先前假设的评估相比，使用这种网络表示法显著改变了GIC危险评估。此外，我们还计算了流经网络中每个单独Transformer绕组的单相GIC。这些Transformer级GIC计算显示了由于Transformer特性和连接而导致的变电站内变压器之间GIC的变化。在某些地方，Transformer级GIC计算会改变危害评估，改变幅度高达一个数量级。在大多数情况下，计算的GIC变化与流过相同变压器的GIC的测量变化相匹配。与大量观察结果的比较证明了Transformer级GIC计算在用于危险评估的模型中的重要性。
During space weather events, geomagnetically induced currents (GICs) can be induced in high‐voltage transmission networks, damaging individual transformers within substations. A common approach to modeling a transmission network has been to assume that every substation can be represented by a single resistance to Earth. We have extended that model by building a transformer‐level network representation of New Zealand's South Island transmission network. We represent every transformer winding at each earthed substation in the network by its known direct current resistance. Using this network representation significantly changes the GIC hazard assessment, compared to assessments based on the earlier assumption. Further, we have calculated the GIC flowing through a single phase of every individual transformer winding in the network. These transformer‐level GIC calculations show variation in GICs between transformers within a substation due to transformer characteristics and connections. The transformer‐level GIC calculations alter the hazard assessment by up to an order of magnitude in some places. In most cases the calculated GIC variations match measured variations in GIC flowing through the same transformers. This comparison with an extensive set of observations demonstrates the importance of transformer‐level GIC calculations in models used for hazard assessment.