Electromagnetic environment under over head power transmission lines 110-500 kV

Super high voltage power transmission lines can be a source of harmful electric and magnetic fields for environment. This paper discusses results of the experimental measurements of these types of fields under real world transmission lines 110, 220, and 500kV. The measurements are fulfilled by using an electric and magnetic fields meter and analyzer. The level of fields parameters at frequency fifty hertz is highest and can exceed permitted maximum for people. The most visible components in field spectra are third and fifth harmonic. The level of magnetic field components does not exceed permitted maximum values for professional and civil people. The change of the ground relief under transmission lines can significantly change level of electric field. This level can exceed the permitted level for people. © 2012 IEEE

Measurement of super high voltage transmission line electric field effecting on the environment

Alterative current transmission lines with voltage of 500 kV are the most powerful source of electro-magnetic non-ionizing radiation. The investigation of radiation effect on technical personnel began in Russia as early as 1953 after the construction of the first 220 kV transmission lines, when the first signals of health worsening of workers appeared. The research results which are presented in this report was carried out by the authors during the period from 1997 to 2007 on different enterprises of main network systems of the Ural and Western Siberia Russia. The experimental investigations were carried out near functioning line of 500 kV, in a zone of the greatest electric field intensity. The method of passive experiment was used during the research. It assumes the measuring by in advance planned combinations of factors which may influence on the considered parameters. At the first stage it was the parameter the electric field intensity (50 Hz frequency). The factors which theoretically can influence on the value of electric field intensity are the following: Voltage of transmission lines of 500 kV; Load current with position of its influence on heating of the transmission line in compare to air temperature and change of line sag over the ground; Atmospheric effects (including air temperature, absolute and relative air humidity, wind speed, speed pressure of wind). The correlation analysis was made by using of received experimental results. According to the results of the correlation analysis, it was made a conclusion that the greatest influence on the amount of electric field intensity under transmission line is made by the factors that can change the line sag and consequently the distance from current-carrying parts to points of measurement. Besides, the distance from current-carrying parts to ground surface is influenced by the change of relief where transmission lines run. Local rising and lowering of the ground level under this part of transmission line may lead to considerable change the electric field intensity, bias area of maximum intensity from line centre, and distort the symmetric picture © 2011 IEEE.IEEE Region 4 (R4

Staff protection in super high voltage electric substations by using of the electric field measurement devices

The paper shows the ability to protect electric power substations personnel from the harmful effects of the super high voltage electric field by using mobile electric field measurement devices, which are placed in mans helmet close to head. The results of numerical modeling of the external uniform electric field distortion by a human body are presented. It is done also the analysis of influence the man physical characteristics and dielectric properties of his footwear sole on the electric field distortion © 2012 IEEE

Investigation of electric field distribution inside 500 kV power distribution substations

The high level electric field intensity produced by high voltage inside 500 kV power distribution substations is harmful for the human (staff) health. It is very important to have knowledge about levels distribution of electric field intensity within power distribution substation. The paper presents results of investigation 50Hz electric field intensity distribution inside 500 kV power transmission substations in Russian Federation. The measurements of electric field intensity were done inside of twenty six power distribution substations. On base of the measurements, the map of the electric field intensity distribution was build for each substation. These maps are used for planning service works or for inspection of equipment on power substations. In the paper, there are estimations, in percents, what value of substation territory is occupied by different levels of electric field intensities. © 2013 IEEE