REMOTE PROTECTION AND GROUND FAULT LOCATION METHOD FOR POWER TRANSMISSION LINE Russian patent published in 2000 - IPC

FIELD: relay protective gear and automatic control of power systems. SUBSTANCE: use is made of additional information concerning phase free from ground fault. Method proposes use of line models whose inputs are supplied with voltage under measurement. Complex loads are connected to model at point of expected fault (arbitrary point). Load magnitude is adjusted so as to ensure that currents at model input coincide with those measured. Resistive loads are chosen to locate fault in transmission line. As distinct from prototype, separate loads are used for probable faulty and good phases of line. Resistive-load setting resistances are introduced for probable faulty phases and impedances for probable good ones. Points where first setting is higher than that measured and second one is lower than the latter are selected. If it is the only point, it is considered fault location point on line. If otherwise, most confident point is chosen from a number of points. EFFECT: improved adaptation of remote protective gear and fault detectors to loading conditions of line preceding ground fault. 2 cl, 14 dwg