New technique for the accurate location of earth faults on transmission systems

A new technique for the single-ended location of resistive earth faults on power transmission lines is presented. Unlike previous work, the algorithm developed has inherent insensitivity to setting errors in the remote source impedance value. This is an important feature, since the remote source impedance often varies significantly under operational conditions. The paper shows the theoretical development of the algorithm, together with a detailed consideration of the hardware aspects. Results are presented for a standard 400 kV transmission line application study