METHOD TO DETECT DISTANCE TO SINGLE-PHASE EARTH FAULT IN POWER TRANSMISSION LINES Russian patent published in 2013 - IPC G01R31/08 

FIELD: electricity.

SUBSTANCE: maximum amplitude of zero sequence current I₀, max is measured on a damaged line after occurrence of a single-phase earth fault. The distance is detected to the single-phase earth fault by the value of instant voltage U_c on the damaged phase at the moment of occurrence of the single-phase earth fault, by the total capacitance C₀ of zero sequence of all lines connected to busbars, by the maximum amplitude of zero sequence current I₀, max on the damaged line after occurrence of the single-phase earth fault and by the running inductive resistance Lrunning of the zero sequence of the power transmission line, in which the single-phase earth fault has occurred, in accordance with the expression D=Uc²*C₀/(I₀, max²*Lrunning).

EFFECT: protection for detection of distance to a place of a single-phase earth fault in three-phase distribution networks of medium voltage class with isolated, compensated or resistor-grounded neutral.

2 dwg