Fault location technique for six phase transmission lines with unsynchronized phasors

Abstract

Six-phase lines utilize right-of-way more efficiently than double circuit three-phase lines, and may be used to meet increasing power transmission demand. However, accurate relaying and fault location algorithms must be developed for six-phase lines. Since six-phase lines are not ideally transposed in the same manner as conventional three-phase lines, fault location using traditional symmetric component methods would result in errors for six-phase systems. Accurate fault location estimation for a six-phase line can be achieved using its impedance matrices, without assuming conductor transposition. The distance to the fault is calculated using the unsynchronized voltage and current phasors from both ends of a faulted line. The synchronization error is considered to be an additional unknown parameter. The fault location technique was tested on a simple transmission system. The distance calculation and the synchronization error estimate were both very accurate.