Effect of resistance to earth improvement on performance of pole earthing

This paper presents a case study about pole´s resistance to earth improvements based on simulation calculations and site measurements. In resonant earthed networks (earthed via Petersen/arc coil) the residual current causes earth potential rise (EPR) on the faulty tower´s resistance to earth. This EPR value, and thus the touch and step voltage has to meet to the electrical safety requirements given in the relevant standards. In some cases the improvement of the suitable resistance to earth value is difficult and furthermore cost-ineffective. The Utilities becomes more and more cost-cautious, therefore cost-effective solutions is required. This paper contains the investigation of three different methods of resistance to earth improvements.