Integral arc models at single phase-to-ground faults and special characteristics of arcing in power cable insulation

The paper presents the results of experimental investigations and calculations of arcing at ground faults in distribution networks up to 35 kV. It is shown that an additional active component in single phase-to-ground current caused by a high-voltage resistor connected to a neutral leads to the change of the following arcing ground fault parameters: voltage recovery rate on the faulty phase after arc quenching, conditions of arcing and arc quenching depending on the insulation material (mass-impregnated paper insulation, polymeric insulation), probability of restrikes. Special features of main stages of arcing ground fault are presented. Integral models of arcing based on conductivity, current and voltage functions for ablation controlled arcs in power cable insulation are proposed.