Relay-Fuse Coordination for Enhanced Protection from Low Impedance fault in Radial Distribution Network

Ensuring reliable and secure operation of power distribution networks requires effective over-current protection, which involves correct coordination between the protective devices such as fuses, circuit breaker and relays. This paper examines the coordination between relay tripping and total clearing time of fuse operation, evaluating protective devices performance as primary and backup protection mechanisms at various fault location. The simulation model is designed using PSCAD/EMTDC software, with the IEEE-13 node test feeder system serving as the basis for analysis. The study focuses on the tripping times of relays and fuses operation during low impedance shunt faults, including single-line-to-ground (LG), double-line-to-ground (LLG), and three-line-to-ground (LLLG) faults. This analysis contributes to improving the design and implementation of protection strategies in modern distribution networks.