磁暴对我国特高压电网的影响研究

随着我国长距离输电的发展，江苏、广东等地曾多次发现磁暴在电网中产生了较大幅度的地磁感应电流(geomagnetically induced current，GIC)，有可能对电网造成危害。文章通过对电网GIC监测数据和地磁数据进行分析，指出除磁暴强度外，大地电性结构、电网结构与参数也是影响GIC水平的重要因素；借助磁暴产生GIC的物理模型并根据特高压电网线路电阻小、输电距离长、采用单相变压器等特点预测未来特高压系统中的GIC干扰问题将更加严重；根据2010年我国特高压规划建立了电网的等效模型，利用典型磁暴感应出地面电场的数值初步估算了各变电站的GIC水平；最后对目前研究中有待解决的关键问题进行了总结，并结合我国国情提出了解决方案。

Effects of Geomagnetic Storm on UHV Power Grids in China

Along with the development of long-distance power transmission in China, it was discovered that high currents induced by geomagnetic storm, namely the geomagnetically induced current (GIC), appeared in Jiangsu and Guangdong provincial power grids as well as in other provincial power grids in China and the secure operation of power grids is possibly endangered by this phenomenon. Based on the analysis on GIC data monitored in power grids and the data of geomagnetism, the authors point out that except the strength of geomagnetic storm, the geoelectric structure of earth as well as the structure and parameters of power grid are also the important factors impacting GIC level. By means of physical model of geomagnetic storm and according to the features of UHV power grids such as low resistance of transmission lines, long distance of power transmission and adopting high-power single-phase transformer and so on, it is predicted that in UHV power grids the interferences caused by GIC will be more serious. According to the UHV power grid planning of China in 2010, an equivalent model of UHV power grid is built and by use of the data of ground electric field induced by typical geomagnetic storm the GIC levels of substations in East China and Guangdong province are preliminarily estimated respectively. Finally, the key problems to be solved in this research are summarized and in accordance with our own national conditions some relevant suggestions are put forward.