Research On Infrared Thermal Image Detecting And Diagnostic Techniques For Insulators

As a main insulation component of power grid, the insulation effectiveness of insulators directly affects the safe operation of power grid. Due to the diverse defects and the atrocious running environment, the accident caused by insulator degradation still frequently occurs. Based on existing research results, in this paper, the infrared thermal image detection and diagnosis for insulators is studied. It will help to better understand the heating mechanism and the insulator infrared thermal image detection and diagnosis techniques.Based on the analysis of the voltage distribution of normal insulator strings inferior insulator strings, the heating mechanism of insulator were studied and analyzed, and the temperature rise were estimated.The laboratory simulation tests and field measurements of the insulator infrared thermal image diagnosis are carried out. The discriminant methods of infrared thermal image diagnosis for insulators are analyzed and discussed. The results showed that, the general thermal image characteristic of porcelain insulator is that, the temperature of the porcelain plate is higher than that of the steel cap. As to the porcelain plate, the farther the position is from the insulator string axis, the lower the temperature is. The temperature difference between adjacent insulators is very small. Compared with the normal insulator string, for the inferior insulator string, the maximum temperature difference along the insulator string obviously increases.The influencing factors of insulator infrared thermal image diagnosis such as solar radiation, meteorological conditions, surrounding heat source, and detection angle and distance were analyzed and discussed.The appropriate measueres to reduce the error caused by the influencing factors are put forward。...