FIELD TEST METHOD FOR DIFFERENTIAL RELAY USING EXCITATION INRUSH CURRENT

摘要

PROBLEM TO BE SOLVED: To provide a field test method for a differential relay using an inrush current capable of enhancing a reliability of an operation test of the differential relay by omitting disconnection/connection work and simplifying the operation test by omitting a power source for testing.

SOLUTION: Power equipment 13 has a power source 11 connected to its upstream side and an inductive instrument 12 comprising a transformer and/or a reactor connected to its downstream side. First current detecting devices CT1 and CT2 are respectively installed on the upstream side and the downstream side of a protection object section of the equipment 13. The field test method detects an abnormality in the protection object section by using current values i1 and i2 detected by the detecting devices CT1 and CT2 and further makes a judgement on connection of the relay 16. The inductive instrument 12 is turned on, and then the connection of the relay 16 is judged to be good or not on the basis of a shift between waveforms of both excitation inrushing currents inputted to the relay 16 by power-on of the instrument 12.

COPYRIGHT: (C)2004,JPO