由于弧垂的存在,架空线路不同位置的对地高度并不相同.常用的电磁暂态仿真软件将线路平均高度作为线路高度,并按均匀传输线进行计算,与实际不符.该文提出一种架空线路电磁暂态仿真中弧垂的处理方法.该方法仍将架空线路视为均匀传输线,在保证波速度不变的条件下计算线路等效对地高度,并通过拟合的方法分析了等效高度与线路各物理参数之间的函数关系,得到了等效高度的近似计算公式.最后,通过实际算例对比分析了该文方法与电磁暂态仿真软件中所用方法的精度.结果显示,该文方法可在基本不增加计算量的基础上有效提高仿真精度.“,”Due to the presence of sag, the heights of overhead line at different locations are not the same. The common electromagnetic transient simulation software takes line average height as the line height and regards the line as a uniform transmission line. It is inconsistent with the actual situation. In this paper, a method for dealing with sag of overhead line in electromagnetic transient simulation was presented. In this method, the overhead line was still regarded as a uniform transmission line, and the equivalent height of the line was calculated under the condition that the wave velocity was constant. The function relationship between the equivalent height and the physical parameters of the line was analyzed by fitting method. The approximate calculation formula of equivalent height was obtained. Finally, the accuracies of the proposed method in this paper and the method used in the electromagnetic transient simulation software were analyzed by a practical example. The results show that the proposed method can improve the simulation accuracy effectively without increasing the computational complexity.