有限元法分析特高压直流线路对人体的影响

为解决特高压直流输电线路对人体影响的问题,引入有限元的数值计算方法,计算了±800kV直流输电线路周围的合成电场和离子电流并建立了人体仿真模型以选取合适的人体介电常数。结果表明:站立时人体模型的最大电场强度为19.15kV/m,行走时的人体模型最大电场强度为18.193kV/m。最大电场强度均在头顶处,最大离子电流密度出现在脚部,下半身的离子电流密度大于上半身。综合考虑输电线路对人的影响、经济性和裕度的情况下,推荐了导线对地的平均高度,在居民区为22m,荒郊区为20m。

Analysis of Effects on Human Body of UHVDC Transmission Line Based on FEM

Ultra High-Voltage Direct-Current has many advantages in long distance transmission. It is playing a key role in electricity transmission from West to East in China. However, it has caused some problems, such as influence on the stability of AC power system, DC bias of transformer, overvoltage, et al. The effect of electric field of UHVDC transmission line on biology, especially human, never should be neglected. Based on FEM, in this paper the ionized field and ion current, generated from the conductor of 800 kV UHVDC transmission conductor, were calculated. By building human body model and setting boundary conditions, the effects on human caused by ionized field and ion current was analyzed. Human's relative permittivity is not homogeneous. Its range is from 1 105 F/m to 2 105 F/m. The results show that the ionized field strength of head is maximal, which is 19.15 kV/m for standing body model and 18.193 kV/m for walking body model. Generally, ionized field strength of upper body is greater than low body's. There are serial factors to decide the high of transmission line, including electric field effect, economy, and insulation, et al. According to the calculation and these factors, the average high of UHVDC transmission line is suggested to be 20 m, and that number of residential place is 22 m.