Performance of a digital distance relay on a six-phase transmission line

This paper addresses the protection issue of six-phase power transmission systems which have emerged as a result of the search for compact and efficient power transmission systems. Performance of the ground, line and the directional impedance algorithms of a digital distance relay on a six-phase power transmission line under various short-circuit fault conditions is reported. The distance relay algorithm assumes the availability of all six currents for processing and therefore the ground impedance algorithm is different to that of a standard three-phase distance package. The results presented are based on offline fault studies on a hypothetical six-phase power transmission line model.