Active fault location in distribution network using time-frequency reflectometry

Abstract

In this work a new single-ended method for fault location in distribution networks is proposed. The method is an active traveling wave fault location, which transmits a Gaussian chirp through the line and applies the cross time-frequency reflectometry in order to find the exact location of the fault with 150 meter tolerance. The method functions in the offline post fault condition, where the system is disconnected. The bandwidth of the proposed method is at least one order of magnitude smaller than its passive counterparts. Furthermore, not only is the method capable of locating the exact distance of the fault away from the relay location, but it also finds the exact line in radial configuration of distribution network. Another characteristics of this method is its immunity to series capacitive compensated transmission line, voltage level, fault phase, fault inception angle, and fault resistance. Another important property of the method is its ability in locating high impedance faults. The method capabilities are verified using PSCAD/EMTDC simulation based on phase-dependent and frequency-dependent models for distribution network lines. An error parameter is defined to compare the method efficiency for different fault types, fault locations, and system configurations.