FAULTY SECTION LOCATING METHOD FOR TRANSMISSION LINE AND FAULT MACHINE LOCATING METHOD FOR POWER FACILITY

摘要

PURPOSE: To locate a faulty section by observing the peculiar variation of current induced in an overhead earth wire at a plurality of points along a transmission line and then inspecting the observed waveform. ;CONSTITUTION: A current transformer 6 picks up the current flowing through an overhead earth wire 2 constantly at each observing point. Output from the current transformer 6 is digitized by an optical data multiplex transmitter 7 at a predetermined sampling time and transmitted over an optical fiber cable 4 to an evaluating section 5. The detected data is stored sequentially, while being updated, in a waveform memory 11 at the evaluating section 5 up to a predetermined number of samples corresponding to several cycles of commercial frequency. A CPU 8 compares every detection data with a preset trigger level being set by a trigger setting switch 10. A trigger is generated when the detection data is higher then a positive trigger level or lower than a negative trigger level. Thereafter, the memory 11 stores the waveform data for several preceding and following cycles.;COPYRIGHT: (C)1995,JPO