An Optimized Infrared Detection Strategy for Defective Composite Insulators According to the Law of Heat Flux Propagation Considering the Environmental Factors

Composite insulators have been extensively adopted in electric transmission lines due to their preferable resistance to contamination flashover. To generally ensure the function of power networks, it is of crucial importance to perform regular online detection and the timely renewal of poor-quality insulators. As the most extensively employed method for the online analysis of composite insulators, infrared (IR) detection is defective based on the false detection rate and the high rate of undetected inner defects. Via numerical simulation and analysis and a test of the simulation model, this paper seeks to systematically ascertain how the defect temperature and IR results are related to each other for different types of conditional thermal defects in composite insulators, especially the relationship between humidity and heating. Finally, considering our previous findings and the on-site feasibility of the methods, some suggestions for IR detection methods regarding composite insulators are proposed. The findings of this paper are conducive to elucidating the conduction of heat flow through the composite insulators and reducing the false detection rate arising from moisture and inner defects. Furthermore, the optimized IR detection method targeting high humidity areas can also be valuable in reference to other power supply units.