SUPPRESSION OF THE ATMOSFERIC OVER-VOLATGES IN GROUNDING NEUTRAL CONDUCTOR LOW VOLTAGE GRIDS
Abstract
This article describes the problems of overvoltage discharge in low-voltage distribution networks in areas with high soil resistivity. A practical example is described in detail, which refers to the Vrgorac-Gomila transmitter located on the Ilica Glavica hill. The transmitter is connected to the distribution network by an overhead low-voltage self-supporting cable bundle (SKS) from TS 10/0, 4 kV Podprolog 1 . Since this is an area with high soil resistivity, and therefore an unsatisfactory transmitter grounding, all overvoltages that occurred in the transmitter area were transmitted to the TS and the associated low-voltage network via the neutral conductor of the SKS. In this case, an innovative approach was used, so that 100 meters of underground cabling was carried out in the middle of the SKS in question. As the neutral conductor of the underground part of the line, an exclusively 2x 50 mm² copper cable grounding was used for the purpose of discharging overvoltages into the ground.
