METHOD OF MEASUREMENT OF DISTANCE TO EARTH FAULT POINT Russian patent published in 2017 - IPC G01R31/08 H02H3/00 

FIELD: electricity.

SUBSTANCE: method of measuring the distance to ground fault in high-voltage electrical networks comprises the following stages. A high frequency signal with wavelength is supplied to the damaged phase considerably longer than the length of the outgoing line from the substation; at the same time vector values of damaged phase voltages are measured at different points and with use of known values of complex resistances between these points, phase currents are determined in these sections. The distance to ground point from the nearest point of voltage measurement is determined as ratio of reactive component of voltage to current. The distinctive features of the invention are: in the absence of branches between the measurement points of the voltage measurements, there is practically no error in the current measurement; due to the relatively high level of high frequency current by the transmitter, it is easy to detect a damaged branch and tune away from interference with a frequency of 50 Hz; the active resistance at the ground fault does not introduce an error in the determination of the distance.

EFFECT: increased accuracy of distance measurement to earth fault in branched high-voltage lines.

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