Performance of Directional Relay Protection in the Presence of STATCOM

Abstract

The integration of STATCOM devices in transmission systems provides important operational benefits but may influence protection performance during fault conditions. This paper investigates the performance of directional relays in the presence of a STATCOM integrated into the power grid. The study was carried out using MATLAB/Simulink simulations. The results show that although the STATCOM modifies short-circuit current and voltage for faults occurring beyond its location, the directional relay consistently detects the correct fault direction. The study also proposes the installation of directional relays at the STATCOM bus as a corrective approach to limit the influence of STATCOM on existing protection relays. The results demonstrate that the proposed approach ensures accurate fault detection and improves overall protection coordination in STATCOM-integrated power systems.