Speedy Detection of Symmetrical Faults During Power Swing

Abstract

Small and large disturbances in power system may sometimes lead to sustained oscillation in three-phase power, often termed as ‘power swing’ in the literature. Power swing is a balanced phenomenon and may be indistinguishable from a three-phase fault. Transmission lines being protected by distance relays may be incorrectly de-energized because of a power swing. So, three-phase faults should be discriminated from power swing with high reliability and dependability. In this study, a novel symmetrical fault detection technique has been proposed with dual use line relays for the first time. The proposed algorithm has been verified for a large number of fault scenarios including series compensated lines with single machine infinite bus and western system coordinating council-9 bus system. It has been seen that the proposed algorithm is giving fast detection of three-phase faults during power swing with high accuracy.