Implementation of Voltage Sag Based Fault Localization Algorithm in Nepalese Distribution System Considering the Impact of Fault Resistances

Reliability is a significant challenge in the Nepalese distribution system, primarily due to the extensive lengths of distribution feeders, some of which span over 100 km, including all branches. In such long feeders, fault localization, particularly in cases of insulator puncture or tree contact, takes considerable time, delaying fault clearance and service restoration. This paper proposes a novel voltage sag-based fault localization algorithm tailored for the Nepalese distribution system. The algorithm utilizes both synchronized and non-synchronized time measurement devices to compare calculated and measured voltage sag errors for accurate fault distance estimation. The method was validated using simulations of a real Nepalese distribution system in OpenDSS and Python. Results demonstrate that the maximum error in calculated fault distances compared to actual fault locations was 3.01% for bolted faults. This approach provides a reliable and efficient solution for fault localization, significantly enhancing system reliability and fault response times in the Nepalese context.