两回高压直流输电线路交叉跨越时地面合成电场计算

高压直流输电线路交叉跨越是我国特高压技术发展中可能出现的新问题。为了建设满足电磁环境要求的直流输电工程,应当研究相应的合成电场预测方法。由于两回直流线路相互影响,交叉跨越区域内合成电场呈复杂的三维分布。本文提出一种两回直流线路交叉跨越时地面合成电场的计算方法,该方法基于三维通量线法,采用模拟电荷法计算标称电场,利用Deutsch假设计算合成电场。通过在实验室内搭建直流导线交叉跨越试验平台,对计算方法进行验证。基于该方法,对±800k V线路跨越±500k V线路时地面合成电场的分布进行研究。与一回±500k V线路单独存在相比,±800k V线路以90°跨越±500k V线路时,地面合成电场峰值基本不变,但分布规律更为复杂。

Simulation of Total Electric Field under the Crossing of Two Circuit HVDC Transmission Lines

The crossing of two circuit HVDC transmission lines is a new problem in the development of HVDC transmission technology in China.The distribution of total electric field under the crossing area is a 3D problem due to the transmission lines interact with each other.In order to meet the requirements of the electromagnetic environment,the corresponding electric field prediction method should be researched.Based on three-dimensional flux tracing method,a method to predict the total electric field under the crossing of two circuit HVDC transmission lines is proposed,where charge simulation method and Deutsch assumption are used to solve the nominal electric field and the total electric field,respectively.A reduced-scale experimental model is set up in the laboratory to testify the validity of the method.The method is then used to simulate the ground level total electric field under the crossing of ±800kV and ±500kV HVDC transmission lines.Compared with single circuit ±500kV transmission line,the top value of ground level total electric field is hardly changed when the ±800kV and ±500kV lines cross in 90 degrees,but the distribution of electric field is more complex.