Travelling-wave-based protection of transmission line using single-end data

Abstract

This study presents a travelling-wave-based protection method for a two-terminal line using single-end data. The method uses polarity of the voltage and current travelling waves to decide the direction of fault. The magnitude and the arrival time of first incident current travelling wave, its reflections returned from the fault point and the remote bus at the relay point is used for the protection purpose. It includes a technique to discriminate reflection returned from fault point or remote bus, based on reflection coefficient of current travelling wave to locate the exact location of fault. For the case, when reflections returned from fault point, and remote end are not discriminable, a relation is formed using arrival time of first incident current wave, its reflections returned from the fault point and the remote bus to identify the internal fault. Using location of fault and the relation formed, protection decision is derived. Results for different fault types, fault locations, fault resistances and fault inception angles in a power system demonstrate the accuracy of the proposed method. Comparative assessment with available method is also provided.