FIELD: power engineering.
SUBSTANCE: invention is used in the field of power engineering to determine the location of a single-phase earth fault (SEF) on power lines under operating voltage. The method consists in measuring the zero-sequence voltage on the buses common for connections, as well as zero-sequence currents in the connections and the voltage of their phases, fixing the occurrence of a SEF by increasing the zero-sequence voltage on the common buses above a given value, while monitoring the absence of a double-circuit mode in the network on ground, identifying the damaged phase by decreasing the voltage of one of the phases of the common buses below a predetermined value, forming a circuit for a short-term current of a double two-station earth fault by a forced selective earth fault through the current-limiting resistor of one of the intact phases of the common buses, identifying the value of the emergency components of the currents of each of connections, determination of the connection and its section with the SEF using the correlation analysis of the indicated emergency components of the currents and its disconnection. At the same time, a circuit is repeatedly formed at specified time intervals for a short-term flow of a double two-station -fault current to ground, a correlation analysis of the emergency components of the currents of each of the connections is carried out, taking into account the path of the artificially created pulse current and the phase relationships of the emergency components, the triggering of the corresponding autocorrelation measuring relays is formed. the introduced relay protection devices installed in the circuits on the path of the current of the double two-station earth fault between the fault location and the current-limiting resistor, upon detecting a given time sequence of artificially created current pulses and identifying the expected autocorrelation function, determine the place of the SEF by the triggered autocorrelation measuring relay, and disconnection connection and its section with the SEF are carried out with a time delay selected according to the stepwise principle with an increase at each step towards the place where the current-limiting resistor is installed.
EFFECT: increased selectivity and technical perfection of protection.
3 cl, 4 dwg
