METHOD AND APPARATUS FOR DETERMINING DISTANCE TO PHASE-TO-EARTH FAULT

摘要

Method and apparatus for determining a distance to a phase-to-earth fault on a three-phase electric line of an electric network, the apparatus comprising means (40) for determining,during a phase-to-earth fault (F)on the three-phase electric line (30), values of a residual voltage of the electric network and a zero-sequence current of the electric line at a measuring point (40) when a neutral to earth admittance of the electric network outside the electric line has a first value and when the neutral to earth admittance of the electric network outside the electric line has a second value different from the first value; and means (40) for determining the distance to the phase-to-earth fault (F) from the measuring point (40) on the basis of the determined residual voltage and zero-sequence current values.