Geomagnetically induced current (GIC) in utility systems such as electric power grids occurring during extreme geomagnetic storms can exceed the tolerance limit of the systems, which can cause serious system damages. It has therefore been important to evaluate the GIC levels in the utility systems. This study presents the simulation and analysis of GIC levels in the Shandong 500 kV power grid system consisting of 34 substations under a variety of uniform induced geoelectric fields. The line type, substation grounding resistance, and other influencing factors are included in the simulations. The results show that the GIC level varies largely in the 34 substations. In 11 substations, the GIC exceeds 100 A and it reaches up to ∼200 A in two substations for an assumed 1 V/km induced electric field. The changes in the GIC distribution are found consistent with the direction changes of the electric field. Utilizing the directional sensitivity, we calculate the maximum GIC level for the optimum direction for all substations. By combining this information with statistical tools, we propose a method for identifying the key substations which are most vulnerable. The result can provide suggestions for GIC disaster prevention and mitigation, substation site selection, monitoring equipment installation, and so on, in Shandong province.

中文翻译：

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山东电网地磁感应电流水平的仿真分析

公用事业系统（例如在极端地磁风暴期间发生的电网）中的地磁感应电流（GIC）可能超过系统的容限，这可能导致严重的系统损坏。因此，评估公用事业系统中的GIC级别非常重要。本文研究了山东500 kV电网系统中GIC电平的仿真和分析，该系统由34个变电站组成，并受各种均匀感应地电场的影响。仿真中包括线路类型，变电站接地电阻和其他影响因素。结果表明，在34个变电站中，GIC级别存在很大差异。在11个变电站中，GIC超过100 A，并且在假定1 V / km感应电场的情况下，两个变电站中的GIC达到〜200A。发现GIC分布的变化与电场的方向变化一致。利用方向灵敏度，我们为所有变电站的最佳方向计算了最大GIC电平。通过将此信息与统计工具结合起来，我们提出了一种识别最易受攻击的关键变电站的方法。研究结果可为山东省GIC防灾减灾，变电站选址，监控设备安装等提供建议。