基于上流有限元法对高压直流输电线路下合成电场的研究

Research on Total Electric Field beneath HVDC Power Lines Based on Upstream Finite Element Method

高压直流输电线路产生的地面合成电场和离子流密度是设计和建设输电线路时应考虑的2个主要电磁环境指标。为预测高压直流输电线路的电磁环境问题,基于上流有限元法开发了相应的分析预测软件。同轴圆柱结构的解析解和实验线路的测量数据验证了该方法的有效性。最后,分析了双极线路情况下线路高度、极间距和表面状况以及单极情况下风速对地面合成场强和离子流密度的影响,这些结果对设计高压直流输电线路具有一定的指导意义。

Two principal environment indices, i.e., total ground electric field strength caused by HVDC transmission line and ionic current density, should be considered in the design and construction of HVDC transmission lines. To forecast the electromagnetic environment of HVDC transmission line, based on upstream finite element method （FEM） a corresponding analysis and forecasting software is developed. The effectiveness of upstream FEM is validated by both analytical solution of coaxial cylinder structure and the measured data from experimental transmission line. Finally, the impacts of the height, pole spacing and surface condition of transmission line on total ground electric field strength and ionic current density under dipole operation mode as well as the impact of wind speed on them under monopole operation mode are analyzed. These analysis results are available for reference in the design of HVDC transmission lines.