中文摘要：

合理设计高压直流模拟试验线段,需要研究线段长度与地面合成电场分布的关系。为此,给出了一种利用点电荷求解较短试验线段标称电场的优化模拟电荷法,并在此基础上,给出了基于Deutsch假设计算其地面3维合成电场的方法。通过计算和对比分析,得到如下结果：当试验线段的长度约为其高度的6倍时,在约1%的误差范围内,可将其当作无限长直导线来处理,进而得到线段中点处的导线表面电场以及中点下方地面标称电场和地面合成电场的横向分布。因此,试验线段的长度可在搭建之前根据试验目的、误差要求及具体导线的结构参数通过计算来确定。

英文摘要：

For reasonable designing a high voltage direct current（HVDC） simulation test line section,it is necessary to study the relation between the length of the line section and the distribution of total electric field at the ground level.Therefore,we put forward an optimized charge simulation method using point charges to calculate the nominal electric field around a relatively short test line section,and proposed a calculation method based on the Deutsch assumption for the three-dimensional total electric field at the ground level.Several conclusions are drawn by calculations and comparative analyses： when the length of test line section is about six times as much as its height,within an error range about 1%,the line section can be considered to be an infinitely long conductor,which can be adopted for calculating the electric field on the surface of conductor at the center of test line section and the lateral distributions of the nominal and total electric field at the ground level under the center of test line section.It is concluded that,before a test line section is constructed,its length can be ascertained through calculations according to the experiment purpose,the error limit,and the structural parameters of a specific conductor.