Patent ID: 8462004

Claim:
A method for producing a fault signal identifying a location of a ground fault on a line between two line ends, which comprises the steps of: measuring a voltage and a current at each of the two line ends, with measured values being formed; determining a harmonic component contained in one of a zero phase-sequence voltage and a zero phase-sequence current, as well as a decay time constant for each of the two line ends, using the measured values; forming a magnitude and a phase of a harmonic vector measurement variable in each case using the harmonic component and the decay time constant for each of the two line ends, wherein a time reference point of the phase of the harmonic vector measurement variable relates to a time of the ground fault detection at a respective line end; rotating the harmonic vector measurement variables formed in this way, starting from the respective line end, to a time in a past; determining the time in the past and a location on the line at which rotated-back harmonic vector measurement variables have at least approximately a same magnitude and at least approximately a same phase, and the location on the line determined is regarded as the location of the ground fault; and outputting the location with a fault signal.