Accurate Transmission Line Fault Location Considering Shunt Capacitances Without Utilizing Line Parameters

Abstract

This article describes a novel and accurate algorithm to determine the fault location on power transmission lines without requiring line parameters. Voltage and current measurements at the two ends of the transmission line during the fault are utilized for fault location, and no pre-fault data are needed. In the past, a two-terminal method has been proposed based on a simplified transmission line model with no shunt capacitances. This article presents a new and accurate method considering line shunt capacitances for unbalanced faults. In deriving the unknown fault location, the line parameters, including series impedance and shunt capacitance, are treated as unknown variables as well. Approaches based on both synchronized and unsynchronized measurements are described. Since there is not enough information in three-phase balanced fault cases, shunt capacitances are not considered for balanced faults; however, the method for balanced faults still proves to be quite accurate. The chief merit of the algorithm is that only voltage and current measurements during the fault are required, and there is no need to worry about line parameters in order to pinpoint the fault location. Evaluation studies based on simulated data have indicated that the new approaches yield quite accurate results.

Keywords:

• transmission line fault location
• line parameters
• power system protection