Enhancement of Distribution System Reliability with Distributed Generation

Abstract

This study examines how reliable the Mojo new distribution substation is and suggests ways to improve it. The main causes of the current system's reliability issues include short circuits, earth faults, overloads, aging equipment, and poor maintenance and operation practices. In this study, we used ETAP 19.0.1 software to simulate the existing system and incorporate solar distribution generators. The reliability indicators of the current system do not meet Ethiopian standards based on the results. By adding distributed generators, the reliability indices improved significantly, reducing interruption duration and the number of interruptions per customer per year while increasing availability. According to the simulation results, installing distributed generators at selected feeders improved the SAIFI value by 61.7%, the SAIDI value by 87.15%, and the ENS value by 87.08%. Additionally, the ECOST decreased from 6.3 BETB/year to 105 METB/year, with an average revenue saving of 6.25 BETB/year. The study recommends connecting distributed generators to the existing system, and pre-maintenance (replace aging equipment and tree trimming) enhances the overall reliability of the network.