摘要：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.
