| 摘要 |
PCT No. PCT/DE95/01524 Sec. 371 Date Jul. 21, 1997 Sec. 102(e) Date Jul. 21, 1997 PCT Filed Oct. 25, 1995 PCT Pub. No. WO96/13888 PCT Pub. Date May 9, 1996The invention concerns a process for detecting a ground fault in an electric power transmission line with three phase conductors where, upon response of the protective device, a fault identification signal indicating a single-pole or multipole fault is generated by comparing currents and voltages with predefined limit values. To reliably distinguish not only between a single-pole and a multipole ground fault, but also to reliably determine the phase conductor affected by the ground fault in such a process, measured quantities, corresponding to the currents of the zero phase-sequence system and the negative phase-sequence system, are formed when no fault identification signal is present. In the event of a ground fault of one phase conductor, when the phase angle between the two measured quantities drops below a predefined limit phase angle, an auxiliary signal is generated. Another auxiliary signal is generated when the currents in the two other phase conductors drop below a fraction of the ground current. A logic circuit emits a fault identification signal indicating a ground fault of one of the phase conductors when both auxiliary signals are present.
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