中文摘要：

地磁扰动（geomagnetic disturbance,GMD）感应地电场通过接地的中性点作用于电网产生地磁感应电流（geomagnetically induced currents,GIC）,给安全运行带来不利影响。海岸效应导致沿海地区地电场出现局部增强,显著影响GIC在电网中的分布。探明海岸效应对地电场畸变及GIC分布的影响程度是深入研究电网磁暴灾害的基础。建立了模拟海岸地区大地电导率结构的薄壳模型,基于有限元法求解了感应地电场的分布;分析计算结果,得出了电导率、频率、分界面距离等因素对GMD感应地电场畸变的影响规律;通过设置输电线路模型定量分析了海岸效应和电网GIC增强现象之间的关系。提出的方法和结果可为我国电网GIC风险评估、防治策略制定等提供理论依据。

英文摘要：

Geomagnetically induced currents （GIC）, driven by induced geoelectric field of geomagnetic disturbances （GMD） through grounded neutral points, bring adverse effects on safe operation of power networks. Coast effect can significantly influence GIC distribution in power grid because of local geoelectric field increase in coastal areas. It is important to investigate influence of coast effect on geoelectric distortion and GIC distribution for deeply understanding risk of magnetic storms in power system. This paper established a thin sheet model to simulate conductivity structure of coastal areas, through which distribution of induced geoelectric field is calculated based on finite element method. Calculation results show how geoelectric field distortion at coast area is influenced by conductivity, frequency and distances to land-sea interface. With aid of an imaginary power transmission line model, GIC increment in power grid due to coast effect is calculated and analyzed. The method and results could be helpful for power system to access and control GIC risk.