FIELD: power industry.
SUBSTANCE: power supply line (10a) is divided with switching devices (13a-d) into a variety of sections (14a-c), with that, measuring device (15a-d) is associated with each switching device (13a-d). Each measuring device (15a-d) records a current signal at measurement point (16a-d) located in the zone of the corresponding switching device (13a-d), which specifies the current flowing at the corresponding measurement point (16a-d), digitises a current signal to shape current samples and determines the measured value of current from current samples. Each measuring device (15a-d) shapes a delta value of current as difference between an instantaneous measured value of current and the earlier measured current value that was determined earlier by a certain number of periods of current signals, compares it to a threshold current value and recognises a current surge when the delta value of current lies above the threshold one. Each measuring device (15a-d) sends the first status message specifying the current surge, and a fault localisation device detects a fault as that located in that section (14a-c) of the power supply line, which is restricted on one of its ends with switching device (13a-d), the measuring device (15a-d) of which has detected the current surge, and on the other end - with switching device (13a-d), the measuring device (15a-d) of which has detected no current surge.
EFFECT: improving sensitivity and reliability of protection.
18 cl, 2 dwg
