Thermal Inspections Prioritize Maintenance Needs at Substations

Time: 2021.05.25

Among the best known technologies to assess the condition of power network assets are infrared and ultraviolet imaging. Both have been used for decades and both rely on specialized cameras that have evolved towards more portability, improved data storage and sharing and greater ease in assessing the severity of any problem identified.

The continued existence of these two imaging technologies has made some wonder whether they are complementary and must be used together or whether they are rather alternatives to detect the same incipient problems. The answer is that each technology offers its own specific benefits when it comes to locating certain types of defect. In general, it can be said that infrared imaging records presence of internal heat due to elevated leakage current while ultraviolet imaging detects presence of corona due to high electric field near surfaces. The first phenomenon depends on an internally-generated heat source and the second on surface condition. Both situations represent a potential hazard to continued safe operation of a line component or equipment at a substation and both are a reason for either closer scrutiny or immediate remedial maintenance.

Several years ago, INMR accompanied an expert on an infrared inspection of a 138 kV substation located near the Gulf Coast of Florida.