带弧垂特高压交流输电线路的电磁剂量学分析

Analysis of electromagnetic dosimetry by ultra high voltage AC transmission line with belt sag

采用Comsol仿真软件和人体模型计算分析倒三角较贴近实际的带弧垂特高压交流输电线路对人体产生的电场效应,并与理想直导线的结果进行对比。结果表明,人体以及人体附近电场和感应电流分布不均匀,体外电场最大值集中于人体头部表面上方,关节连接处和端部的电场、感应电流密度较大。带弧垂特高压输电线路在人体各组织产生的电场和感应电流密度均较理想笔直导线线路下高约17%-19%;与国际非电离辐射防护委员会（International commission on non-ionizing radiation protection,ICNIRP）导则限值相比较,电场强度无论是对专业人员还是普通民众均在ICNIRP导则限值范围内;而感应电流密度除人体腿部下部、头皮与颈部连接处附近的略高于ICNIRP导则中普通民众的限值外,其他均在ICNIRP导则限值范围内。两种类型特高压输电线路所产生的电磁辐射对专业人员是安全的,对普通民众应注意适当的防护。

The aim is to investigate the electric field effect produced by the ultra high voltage（UHV） AC transmission lines with belt sag on the human body. A simulation software named Comsol and a human body model were used to calculate and analyze the electric field effect caused by the nabla UHV AC transmission lines closely to the reality, and then the result was compared with the one produced by ideal straight lines. The results indicated that in the human and the near-field region, the distribution of electric field and induced current was nonuniform. The maximum electric field focused on the above region of human head surface. The value of electric field intensity and induced current density in the joints of the body were high. Below the actual and ideal straight UHV transmission lines, the electric field intensity and induced current density produced by the belt sag wire in all tissues including central nervous system of human was 17% to 19% or so higher than the ideal straight. Compared with the guidelines of International Commission on Non-ionizing Radiation Protection（ICNIRP）, the electric field intensity did not exceed the threshold value for both occupational exposure and general public exposure. In the aspect of induced current density, except that the value in the lower legs and lower scalp exceeded the limitation of general public exposure slightly, that of the other parts did not exceed the limits of ICNIRP. The conclusion shows that the electromagnetic radiation caused by the two kinds of UHV AC transmission lines is safe for the occupational people. As to the general public, some proper protection must be taken.