Medium Voltage Distributed Network Performance Optimization by Reliability Centered Maintenance Prioritization of Distributed Feeders and DG Integration

Abstract

In 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.