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.