随着全国越来越多的高压直流线路投入运行，地电场观测数据的质量受到严重干扰。本文从高压直流输电干扰对地电场观测的影响机理出发，以江苏地区为例，对其5年来高压直流输电线路对地电场观测数据的影响特征进行分析总结，得出相关结论：①当地电场观测数据受高压直流输电线路干扰时，地电场观测数据会出现畸变，持续一段时间后，不平衡电流消失，数据恢复正常；②地电场观测数据产生畸变的方向与观测台站的装置布设方式、接地极相对观测台站的位置有关；③高压直流输电线路接地极距离江苏地电台站较远，同一台站同一方向受同一高压直流输电线路影响的长短极距观测数据变化幅度之比接近1；④不同次高压直流输电干扰在同一台站出现地磁干扰变化幅度一致时，同一台站的地电场观测变化幅度不一定一致，与台站和接地极之间的地下电性结构的导电性变化有关。

More and more high voltage direct current transmission(HVDC)lines are put into operation in China,which has great affected the observation quality and application research of geoelectric field observation data. Based on the influence mechanism of HVDC interference on the observation of geoelectric field,we take Jiangsu Province as a study region,analyze and summarize the influence characteristics of HVDC transmission lines on the observation data of geoelectric field in the past five years in the study areas. The relevant conclusions are as follows:① When the observation data of geoelectric field are interfered by HVDC transmission lines,the geoelectric field will be distorted for a period of time,then the unbalanced current disappears and the data returns to normal. ② The direction of the distortion of geoelectric field is related to the layout of the observation station and the relative position of the earth electrode and the observation station. ③ The ground electrode of HVDC transmission lines are far away from Jiangsu geoelectric stations,and the ratio of the variation amplitude of the long and short polar distance observation data affected by the same HVDC transmission line in the same direction of the same station is close to 1. ④ Even though the amplitude of geomagnetic interference is same in the same station,the variation amplitude of the geoelectric field data in the same station is not necessarily the same,which is related to the conductivity change of the underground electrical structure between the station and the ground electrode. Our above results is of significance for the fast discrimination of HVDC lines,the abnormal implementation of data,and the application research of geoelectric observation data.

P315

中国地震局“监测、预报、科研”三结合课题（3JH-2020022008）、江苏典型城镇地震灾害风险评估项目共同资助