Modeling and implementation of a dual-mode emulator for line distance protection based on minimum line reactance

Abstract

Advances in power system protection and the increasing complexity of electrical networks have created a growing need for flexible and cost-effective platforms for testing and validating protection algorithms. However, academic laboratories still face a lack of accessible experimental platforms allowing researchers to implement and evaluate new protection strategies under realistic conditions. This gap is becoming increasingly significant with the emergence of artificial intelligence and data-driven techniques, which require flexible environments for development, testing, and experimental validation. To address this limitation, this work presents the modeling and implementation of a dual-mode emulator for minimum reactance distance protection of overhead transmission lines, operating in both real-time and offline modes. The proposed system acquires and processes voltage and current signals to determine the minimum line reactance used for fault detection and distance estimation. The developed algorithm is evaluated through simulated fault scenarios under different operating conditions. Results demonstrate reliable fault detection and consistent fault-distance estimation. The dual-mode architecture enables both offline analysis of recorded signals and real-time algorithm evaluation. The proposed emulator therefore provides a practical, low-cost academic platform for research, training, and experimental validation of conventional and emerging protection strategies.