Exploring Fault Detection Algorithms in Differential Relays for distribution Line Protection

This study presents a novel examination of the application of differential protection for distribution lines utilizing an instantaneous fault detection algorithm. The proposed algorithm exhibits a unique simplicity in its restraint characteristics, thereby eliminating the need for complex configuration. Additionally, The efficacy of the employed signal processing techniques to ensure reliable performance against false trips during sudden transients, such as external faults leading to saturation of current transformers is investigated. In order to assess the performance of the proposed algorithm, a comprehensive array of fault scenarios were simulated using the DIgSILENT PowerFactory software on a real-world 20 kV e-distribuzione loop network. The results indicate that the proposed algorithm offers efficient and reliable line protection, and exhibits robustness against variations in fault parameters, close proximity external faults, and current swing situations. In order to evaluate the fault detection response time in comparison to a conventional phasor-based methodology, an alpha plane algorithm was also tested in the same fault scenarios. The results demonstrate that the proposed algorithm exhibits a significantly faster response time. Therefore, it is believed that the proposed algorithm holds the potential for successful implementation in longitudinal differential relays.