Method and a device for fault location in the event of a fault on a power transmission line

摘要

The invention comprises a method and a device for fault lo­cation in case of a fault appearing on a power transmission line between two stations (P, Q) and when capacitive measur­ing transformers are used for voltage measurement. The fault location is performed on the basis of a distance protection equation in which the voltage measured at the measuring sta­tion, in addition to the voltage drop (UPF) across that part of the line which lies between the measuring station and the fault location (F) and the voltage drop across the fault re­sistance, also comprises a voltage which represents the mea­surement error voltage which is introduced by the capacitive voltage measuring transformer. The equation is solved with the aid of linear regression technique. With knowledge of the impedance (ZPQ) of the faultless line and the current in question, the fault position (α = 0 - 1) is determined.