Power Outage Analysis in Electricity Distribution Network: A Case Study of Dugbe Business Unit, Ibadan, Nigeria

This study examines outage patterns in the Dugbe Business Unit of the Ibadan Electricity Distribution Company (IBEDC) to highlight reliability challenges and operational improvements at the distribution level within a large Nigerian franchise area. It combines quantitative reliability metrics, such as System Interruption Duration Index (SAIDI), System Average Interruption Frequency Index (SAIFI), and Consumer Average Interruption Duration Index (CAIDI), with qualitative data from stakeholder surveys, interviews, and archival records to analyse outage frequency, duration, and restoration performance. The study identifies key technical and operational factors driving outages. From 2021 to 2024, SAIFI decreased from 520 to 390 interruptions per customer, while SAIDI dropped from 2,800 to 2,200 hours per customer; CAIDI increased slightly from 5.38 to 5.64 hours. The year-to-date figures for 2025 show similar trends: 250 SAIFI, 1,500 SAIDI, and 6.00 CAIDI. These patterns suggest that prevention measures have improved more quickly than restoration efforts, resulting in fewer outages and lower total disruption, but with slightly longer average restoration times. Root cause analysis reveals that certain technical factors- such as air-conditioning equipment, capacitors, cabling, conductors, transformers, and low-voltage lines- as well as random drivers, explain a significant portion of outages, with a persistent downstream pattern at one substation. We recommend a dual approach: enhance event prevention through risk-based and condition-based maintenance, along with targeted undergrounding, while also streamlining restoration processes via automation, OMS/SCADA workflows, staging crews, and spare parts, as well as standard switching procedures. Although focused on distribution outages and limited by the preliminary nature of the 2025 year-to-date data, this analysis provides a practical model for improving reliability and governance at the feeder and business-unit levels.