高压直流输电对甘肃地电场观测影响分析

以甘肃河西地区瓜州、嘉峪关、高台地电场观测受酒泉一湖南±800 kV高压直流输电工程影响为例,分析了甘肃地电场观测受干扰的异常变化形态和特征,并结合高压直流输电基本原理,对异常机理进行了探讨,定量的计算了不同距离、不同电导率和高压直流输电入地电流等对地电场观测的可能影响。结果表明,在理想状态下,高压直流输电对地电场观测的影响与入地电流成正比,与地电场观测场地距换流站接地极的距离的平方和影响区域的电导率成反比。并采用最小二乘拟合法对干扰进行消除,效果理想。

Effect of HVDC Transmission on Geoelectric Field Observation in Gansu Province

In this study, the interference of Guazhou, Jiayuguan, and Gaotai geoelectric field observations in the Hexi Area of Gansu Province via the Jiuquan-Hunan ±800 kV HVDC transmission project was taken as an example to analyze the changes in anomalies during geoelectric field observation. The anomaly mechanism and the basic principles of HVDC transmission were discussed, and the possible effects of different distances, conductivities, and grounding currents on the observation were calculated. Under ideal conditions, the influence of HVDC on geoelectric field observation was directly proportional to the grounding current and inversely proportional to the square of the distance between the observation site and the earth electrode of a converter station and the conductivity of the affected area. Least square fitting was conducted to eliminate the interference, and the effect was ideal.