地磁场H、D受HVDC输电干扰特征分析

Characteristics of interference from HVDC transmission to the horizontal component and magnetic declination of the geomagnetic field

以受宁东线高压直流(HVDC)输电干扰相对严重的11个地磁台站为主要研究对象,以蒙城台为干扰幅度量取的参考台站,研究了地磁场水平分量H、磁偏角D受HVDC输电的干扰特征.发现H和D受HVDC输电干扰具有同步性和偏向性;同一HVDC输电线路两侧H和D干扰幅度具有线性关系,但线性关系明显弱于垂直分量Z干扰幅度的比例关系;接地极附近台站各自的Z、H、D干扰幅度具有线性关系.之后对H和D干扰产生的机理进行了深入的定性分析.根据得到的干扰特征的结论,提出了以红山台Z、H、D为输入的本研究相关台站的Z、H、D为输出的自动计算方法.经过误差分析,本方法平均误差水平低于国家地磁学科中心当前使用算法误差水平,最高降幅达42.9%.

Taking eleven geomagnetic stations as the research object,this paper analyzes the characteristics of interference from HVDC to the horizontal component and magnetic declination of the geomagnetic field.This severe interference is produced by the Ningdong High-Voltage Direct Current(HVDC)transmission line.In the analysis,Mengcheng is the reference station to measure interference amplitudes of the eleven stations.The results indicate that the H and D interferences by HVDC transmission have synchronism and directionality.The amplitudes of a same HVDC transmission line are linearly dependent.However the linear relationship is weaker than that of Z component.Z,H and D interference amplitudes of stations nearby ground the electrode are linearly dependent.Then,we make an in-depth qualitatively analysis to the mechanism of H and D interference.On the grounds of analysis conclusions,we propose an automatic calculation method which takes the Z,H and D interference amplitudes of the Hongshan station as input and those of other stations as output.The error analysis shows that the average error is significantly less than that of National Geomagnetism Network Center automatic publishing system,with the largest error decrease up to 42.9%.