Environmental analysis of the electric field due to MV overhead lines supported by concrete poles

This paper presents an environmental analysis of the electric field due to MV overhead lines supported by concrete poles with a pole-top-pin construction. A three-phase system of voltages has been applied to an electric model of the configuration and a three-dimensional numerical analysis has been done by using the charge simulation method. The time variation of the electric fields at the frequency of 50 Hz has been numerically computed and the obtained results have been experimentally validated by means of an extensive campaign of measurements. The preliminary set-up checks in order to minimize the perturbation error due to the measurement instrument are described. The rms values of the three components of the electric field have been measured and the data obtained around a MV line, at different heights (up to 2 m from the ground), far and near a supporting concrete pole are reported. A significant result is that the electric field at the pole surface at the height of 2 m is greater than the one at the same level under the line in the midpoint of the span.