GROUND FAULT LOCATOR AND LOCATING METHOD

摘要

PROBLEM TO BE SOLVED: To locate even a faint ground fault by taking waveform parameter correlation between the actually measured ground fault surge waveform of a system and the imaginary ground fault surge waveform of an equivalent circuit modulating the system. SOLUTION: A waveform measuring means 11 converts a received ground fault surge waveform into a digital signal and a waveform analyzing means 12 calculates the waveform parameters of the ground fault surge waveform. A system equivalent network forming means 14 forms a state equation by redesignating the input and output positions from an existing drawing of placement and a system analyzing means 15 calculates a transfer function and outputs the waveform parameters B of the ground fault surge waveform. A waveform parameter comparing means 13 calculates the correlation value of the waveform parameters A, B and a ground fault point/ground fault resistance varying means 16 varies the ground fault point/ground fault resistance from the value thus obtained and feeds the varied value back to the state equation. More specifically, the waveform parameters B are calculated while varying the ground fault point/ground fault resistance variously depending on the comparison results and the ground fault is located at a point where the difference between the waveform parameters A, B is smallest.