ABSTRACT This paper proposes an advanced adaptive protection relay system that leverages IEC 61850‐based wide‐area communication and PLC‐driven decision logic. By integrating real‐time data from multiple substations, the system dynamically adapts relay operations to changing network topologies while maintaining compatibility with existing protection relays through an add‐on architecture. This add‐on approach facilitates easy deployment without major modifications to existing systems, enabling scalable and cost‐effective implementation. A decision tree algorithm provides transparent, deterministic, and rapid fault isolation. The proposed approach was validated through hardware‐in‐the‐loop simulations, demonstrating its practicality, scalability, and effectiveness in enhancing the reliability of power system protection.
