Distance Relaying for the Protection of Modern Power System Networks

Distance relays (DRs) have long been considered one of the most reliable protection schemes for transmission lines (TLs), providing primary and backup protection. However, the increasing complexity of transmission networks, the integration of large-scale renewable energy and dynamic operating conditions present significant challenges to their effectiveness. Traditional DRs protection logic often struggles when networks deviate from predefined configurations, potentially leading to protection failures. Numerous solutions have been proposed in the literature to address individual challenges in distance relaying for the protection of TLs. However, there are only a few review papers which comprehensively cover these issues across multiple domains of problems encountered in modern power system networks. This paper thoroughly reviews the technical, topological, and operational challenges that impact DRs performance, as reported in the literature. It systematically categorizes protection issues and their corresponding solutions available in the literature into twelve key areas: power swings, voltage instability, load encroachment, parallel lines, multi-terminal lines, flexible alternating current transmission systems (FACTS) devices, series compensation, high voltage direct current (HVDC) lines, renewable energy integration, microgrids, high-impedance faults, and cyberattacks. Additionally, the paper identifies emerging research opportunities to tackle the increasing complexity of modern power systems, aiming to foster the development of more robust and adaptive distance protection schemes for TLs.