DETECTION OF FAULT LOCATION IN OVERHEAD TRANSMISSION LINE USING PSCAD

Abstract

Transmission lines at any voltage level are subject to faults. To expedite repairs and restoration of power, it is important to know the location of fault. With a view to achieve this objective a lot of methods have been developed to increase the accuracy. Several methods use voltage and current measurements to find the location of fault. In this method, fault detection technique based on the voltage synchronize method has been proposed. The proposed technique is based . on bus voltage measurement of two terminal transmission lines. Advantages of the proposed technique are, the fault detection is independent from the fault resistance, and inception angle of the transmission line. In the proposed method, fault voltage, pre fault voltage and post fault voltages are used to detect symmetrical and unsymmetrical fault. To determine these voltages, a Thevenin model of the transmission line has been developed. In the proposed technique, current has been -eliminated in the problem formulation. Therefore in this technique the values of the current are not required. Another advantage of this method is non requirement of current transformer. There by eliminating the attendant issue of saturation of current transformer. The proposed technique has been tested on a 100 km transmission line. Simulation studies have been carried out using PSCAD and MATLAB software packages.