Analysis of Poynting's Vector around and inside Human Body Erect on Ground under Power Line.

本研究对识别工频电能流动的坡印亭矢量进行了计算和测量。将坡印亭矢量表示为电场和磁场的矢积，对于时变的电场和磁场，应考虑该矢量的瞬时值和时均(有效)值。从理论上分析了500千伏和18千伏输电线路在距地面1m处的这些值的特点。相关实验是在187kV1ine下进行的。此外，对于人体在电力线下直立在地面上的情况，阐明了人体与坡印亭矢量的相互作用。研究结果如下：利用计算得到的电力线电场和磁场的相量，对坡印亭矢量进行了分析。根据实际负荷功率因数(相电流：1000A)，在距地面1m处的有效功率密度约为kW/m2量级。500kV或187kV垂直双回线路的下部导线下的有效功率密度最大。电场和磁场的传感器被安置在一个导电球体中，传感器的输出被相乘并按时间平均。电场和磁场的波形和时间平均值通过光纤传输，以便用示波器观察。在电能的流动中，坡印亭矢量在人体头部周围得到高度增强。这是因为10KV/m的电场和0.5G的磁场低于人体的平均代谢率。

This research was conducted on the calculations and measurements of the Poynting's vector which identifies the flow of power frequency electric energy. The poynting's vector is specified as the vector product of electric field and magnetic field.For time-varying electric and magnetic fields, the instantaneous and time-averaged(effective)values of this vector should be taken into consideration. Theoretically analyzed were the characteristics of those values at a height of 1m above the ground under 500 and 18kV power lines. The associated experiments were performed under a 187 kV 1ine. Furthermore, the interaction of human body with the Poynting's vector has been made clear for the case where the human body is erect on the ground under power line. The results of this research can be summarized as follows :The Poynting's vector were analyzed by using the calculated phasors of electric and magnetic fields from the power lines. For the practical power factors of the load(phase current : 1,000 A), the effective power densities at 1m above the ground were found to be on the order of some kW/m^2. The maximum density appeared beneath the lower conductors of 500 kV or 187 kV vertical, double-circuit lines.The Poynting's vector was observed on the ground under a 187kV line. The sensors of electric and magneti fields were housed in a conducting sphere, where the outputs of the sensors were mutiplied and averaged as to time. The waveform of electric and magnetic fields and the time-averaged value were transmitted through the optical fibers so that those could be observed with an oscilloscope.The Poynting's vector was found to be highly enhanced around the head of the human body in the flow of electric energy. This is because the electric filds of 10kV/m and a magnetic filds of 0.5 G was found to be smaller than an average metabolic rate of humans.