【摘要】 由磁暴引起的地下感应电场(geomagnetic induction electric field,GIE)会影响电网的安全稳定运行,GIE的大小取决于磁暴时磁场的变化率和周围地下介质的电性结构.本文利用在地表观测的磁场与电场数据,首先求得频率域实际地下三维大地电磁站间阻抗,再结合磁暴时段的磁场数据,计算GIE的频谱,最后通过傅里叶反变换,得到GIE时间序列.本文以日本地区三个长期观测的电磁电台站为例,讨论了站间阻抗的长期稳定性,并选取一次典型的磁暴事件,对本文方法进行了验证.结果表明,合成的GIE与实测数据基本一致,说明利用大地电磁站间阻抗,结合地磁台站数据,可以高精度合成GIE.本文方法有助于定量评价磁暴发生时产生的GIE对电网可能造成的破坏作用.更多还原

【Abstract】 The geomagnetic induction electric field(GIE)is induced by the magnetic storm,and has an big impact on the safe and stable operation of the power grid system.GIE depends on the variation of magnetic field during the magnetic storm and the electrical structure of underground.In this paper,firstly,we estimate the three-dimensional magnetotelluric(MT)quasi-impedance in the frequency domain by using magnetic and electric field data.Then,the spectrum of electric field is obtained by multiplying quasi-impedance with magnetic spectrum from magnetic storm time series.Finally,the GIE time series are synthesized by inversed Fourier transform.Three electromagnetic observatories in Japan,which continuously record the geomagnetic and geoelectric data from 2001 to 2009,were illustrated as an example to show the temporal variation of the quasiimpedance and the advantages of our proposed method.And,the Halloween storm event is selected to verify our approach of predicting GIE.The results show that predicted GIE is consistent with the measured data,and confirm that MT quasi-impedance can used to synthesize GIE with high precision by combining with geomagnetic data.The proposed method can be used to evaluate the possible damage to the power grid caused by GIE.更多还原