METHOD FOR DISTANCE ESTIMATION OF SINGLE-PHASE-TO-GROUND FAULTS IN ELECTRICAL DISTRIBUTION NETWORKS WITH AN ISOLATED OR COMPENSATED NEUTRAL

The paper discusses how current and voltage measurements derived from the substation can be used for single-phase-to-ground fault location i n medium-voltage distribution lines. The networks considered are assum ed to be radially operated with either an isolated or compensated neut ral. In these networks the fundamental frequency ground fault currents usually are so small that no reasonable fault-distance estimate can b e based on them. A possible solution is the utilisation of ground-faul t initial transients. In this paper a method for ground-fault distance estimation, based on the least squares estimation of transient parame ters, is presented.