高压直流输电线对甘肃地磁观测的影响分析及应对措施

Impact and Countermeasures of HVDC Transmission on Geomagnetic Observation in Gansu Province

随着国家电网建设规模的不断扩大,越来越多的高压直流输电工程陆续投入使用,对线路两侧的地磁观测资料造成了不可避免的影响。目前有5条高压直流输电线路对甘肃地磁台站的观测造成一定程度的干扰。通过单台及多台观测资料对比的方法,识别高压直流输电线对地磁观测资料的影响,研究干扰特征,对正确预处理观测资料有重要的意义。结果表明:①高压直流输电对地磁Z分量影响明显,D、H分量不明显;②对地磁观测影响产生的形态主要表现为方波型、缓变型、梯形型、复合型等。通过总结高压直流输电对地磁观测资料影响特征及形态,有助于正确预处理观测资料及为今后实现计算机自动化处理提供依据。

With the continually expanding scale of the national power grid,an increasing number of high voltage direct current(HVDC)transmission projects have been employed;this has had an inevitable impact on obtaining geomagnetic observation data on both sides of the transmission lines.Five HVDC transmission lines currently cause interference at Gansu geomagnetic station,and it is thus extremely important to correctly identify the extent of HVDC transmission interference on geomagnetic observation data to enable its correct preprocessing.In this paper,the influence of HVDC transmission lines on geomagnetic observation data is identified by comparing observation data of a single station with those from multiple stations.The results show that:(1)HVDC transmission has an obvious influence on the geomagnetic Z component,but the influence on the D and H components is not obvious.(2)The HVDC influence forms on geomagnetic observation are mainly a square wave type,slowly changing type,trapezoid type,and composite type.(3)Analyzing the characteristics and forms of HVDC with respect to its influence on geomagnetic observation data is useful for correctly preprocessing the observation data and will provide a basis for conducting automated computer processing in the future.