Comparison of electrical variables of transient process for earth-to ground fault location in medium voltage cable networks

Abstract

Early detection of faulty cable line with single-phase earth fault (SPEF) and SPEF location in the cable line is extremely important for timely fault elimination and restoration of normal power supply. Up to now, there is no effective method for a distant SPEF location in medium voltage cable lines at process voltage. Electrical data of transient processes at insulation damage can be used for single-phase fault location including self-clearing. The best opportunity for study of electromagnetic transients at SPEF in medium-voltage networks and identifying data, which can be used for a distant SPEF location, is a combination of analysis based on the simplified models of electrical networks and computer simulation. The most efficient algorithm for SPEF location can be obtained by measuring the transient voltage of the faulty phase and derivative di 0 (t)/dt at moments corresponding to i 0 (t) crossing the zero value.