FIELD: electrical power engineering.
SUBSTANCE: voltage in damaged phase is registered at buses of power source at initial moment of short circuit and the voltage is approximated by second order polynomial. Absolute maximal value of derivative is determined at the start point of approximation section and it is standardized in relation to breakdown voltage. Approximate distance Lsc to point of short circuit is determined from calculated dependence to point of short circuit from maximal standardized derivative of voltage for specific line in the network. Simultaneously with registration o f damage phase the zero sequence transient current is subject to registration in damaged connection. Highest frequencies are damped in the current by means of electric filter with dynamic cut-off frequency fcut-off=v/Lsc. Onto processed curve of zero sequence current the first maximum is found, time moment t1 which corresponds to the current and time moment 
, where v is speed of electromagnet wave in line, K is factor which changes linearly from 0,1 to 0,2 at increase in approximately measured distance Lsc from beginning of the line to its end. At this section the second maximum with the same sign and its time t2 are determined. Refined distance to point of short circuit is calculated from the relation of Ls=v/2 x(t2-t1).
EFFECT: improved precision of measurement without switching damaged line power source off.
3 dwg
