中文摘要：

高压直流输电线路下方地面的合成电场与离子流密度是线路电磁环境特性的重要参数。旋转式直流电场仪又被称作场磨,是测量合成电场的常用装置。直流输电线路电晕放电所产生的空间电荷在电场中定向运动,分布于整个场域。场磨测量合成电场时,空间电荷进入场磨探头,可能对测量产生影响。为了研究空间电荷对场磨测量合成电场准确性的影响,推导了一维直角坐标系下合成电场与离子流密度的解析关系,设计制作了平行极板的电晕放电实验装置。利用装置的电晕丝网向静电场中注入可控的离子电流,进行了场磨测量合成电场的实验。实验结果表明,空间电荷使合成电场增强,场磨对合成电场的测量值与计算值相符,场磨测量合成电场是准确有效的。通过计算和实验获得了测量合成电场的相对误差,对高压直流线路电磁环境的准确测量提供有益的参考。

英文摘要：

The total electric field and ion current density on the ground beneath the high voltage direct current（HVDC） transmission lines are important parameters of the electromagnetic environment characteristics of transmission lines. Rotating DC electric field mill is a common kind of device to measure the total electric field on the ground. Space charges generated by corona discharge of the lines, move and distribute throughout the whole field, which may have effects on the probe when utilizing the field mill. In order to investigate the effects of space charges on the measurement accuracy of the field mill, analytical relation between total electric field and ion flow density in 1-D Cartesian coordinates was derived, and a corona discharge apparatus with parallel plates was designed and fabricated. The controlled ion flow was generated by the corona discharge device. Experimental results show that space charges increase the total electric field, and measurements by the field mill agree with the calculations. It is accurate and reliable to measure total electric field by the field mill. Relative errors of total electric field between measurements and calculations are obtained, which provide valuable reference in the accurate measurement of the electromagnetic environment of HVDC transmission lines.