Application of Thermal Imaging in Electrical Equipment Fault Detection for Nigerian Power Distribution Networks

Electrical faults in power distribution infrastructure including transformer overheating, loose connections, and insulator degradation are responsible for a significant proportion of power outages in Nigeria's distribution networks operated by electricity distribution companies. Thermal infrared imaging provides a non-contact diagnostic technique for identifying hotspots indicative of developing faults before catastrophic failure. This study evaluates the application of thermal infrared cameras for fault detection in 33 kV and 11 kV distribution substations and overhead line components operated by the Abuja Electricity Distribution Company in the Federal Capital Territory. Thermal surveys are conducted on 45 substations and 80 kilometres of overhead line using a cooled InSb focal plane array camera with thermal sensitivity below 0.05 degrees Celsius. Identified hotspots are classified by temperature differential above ambient following IEC TS 62237 criteria and prioritised for maintenance. Results identify 127 thermal anomalies across the survey area, of which 23 represent severe faults with temperature differentials exceeding 40 degrees Celsius. Transformer tank hotspots correlate with oil level deficiency and overloading. The study demonstrates a 4:1 benefit-cost ratio for thermal inspection relative to emergency repair cost avoidance for the Abuja Electricity Distribution Company. Keywords: thermal imaging, infrared, electrical fault detection, power distribution, Nigeria