Rahwa Berhane2025-06-172024-10-25https://repository.mu.edu.et/handle/123456789/52010.82589/muir-49710.82589/muir-497In today's world, virtually every human activity relies on electricity, either directly or indirectly. Reliable electric power is essential for our daily activities, and this power is delivered through a distribution network. However, numerous issues prevent the continuous supply of electricity to end-users. The main problem on the distribution network are lack of planned preventive maintenance, improper feeder size selection, over load and lack of DG. To address these issues, this work employs a reliability-centered prioritization of feeders for maintenance and integrate a solar PV system to the distribution network using the Electrical Transient Analyzer Program (ETAP) to improve the reliability and availability of electric power. A comprehensive reliability analysis for identifying a feeder R5 as a case study sample, making it the case study for Reliability improvement. By integrating, a DG in the selected feeder results a significant improvement in reliability indices. The System Average Interruption Duration Index (SAIDI) was reduced from 735.43 hours/customer/year to 369.413 hours/customer/year, and the System Average Interruption Frequency Index (SAIFI) decreased from 293.259 per year to 200.30 per year. These reductions represent decreases of 49.77% and 31.7%, respectively. Furthermore, the Expected Energy Not Supplied (EENS) dropped from 46,107.5 MWh to 23106.71 MWh, and the Expected Outage Cost (ECOST) decreased from $2,019,508.5 to $1,012,073.898, indicating an improvement in cost-worth reliability indices and the network's revenue. The reduced reliability indices demonstrate the enhanced performance of the distribution network from a reliability perspective. Implementing a reliability-centered maintenance for the feeders in the conventional distribution network would also improve the reliability of Mekelle city distribution network.enETAPDGReliability-centered maintenanceThesis