A fault point in a line section of a three-phase power transmission line, is determined by measuring currents and voltages at a measuring point arranged adjacent the near end of the section. The type of fault (single-phase/multi-phase ground fault/phase-to-phase fault) is determined and the parameters...http://www.google.com/patents/US4559491?utm_source=gb-gplus-sharePatent US4559491 - Method and device for locating a fault point on a three-phase power transmission line
