Computer Modeling of the Processes Arising During Arcing Ground Faults in 35 kV Resistance Grounded Systems

Abstract

This article represents the results of metallic and arcing phase-to-earth faults in 35 kV overhead distribution networks with high or low neutral grounding resistance. The cylindrical symmetrical channel model of an vertically oriented arc, stabilized by rising convective gas flow, was carried out by ATPDraw software. The oscillograms of phase-to-earth fault currents and striking voltages were obtained with the help of the created computer arc model, as well as oscillograms of temperature evolution in the central channel, resistance, and arc radius. Based on the obtained results, the analysis of neutral grounding resistance efficiency during ground faults was determined. It shows that taking into account the arc equations leads to rapid arc self-quenching. Moreover, the mathematical model of the arc indicates that an increase in the active fault current component to a certain value helped to change a transient arcing combustion mode into a steady one. The obtained results should be used to justify the real number of phase-to-earth faults with arc self-quenching (including during restrikes). And for steady arcing phase-to-earth faults resisting neutral grounding should be used to quickly locate the fault.