For studying the effectiveness of infrared and UV imaging technology to detect zero-value insulators

the infrared thermal images and UV videos of zero-value insulators at different positions on insulator strings under different humidity and contamination are collected. The heat and discharge characteristics of the insulator strings are analyzed. The thermal-electric coupling simulation model is set up by the use of finite element software. The temperature and electric field distributions of the insulator strings under different conditions are calculated and verified. The study shows that in case of contamination and dry condition

the insulator strings are not easy to discharge

the UV imaging method cannot effectively detect a zero-value insulator

the infrared thermal image shows that the temperature rise of normal insulator is significantly higher than that of zero-value insulator. The infrared imaging method can detect effectively the zero-value insulators. In the case of contamination and wet condition

misjudgment may occur in both infrared and UV imaging due to heavy contamination of high conductivity and unevenness of contamination of moisture.