Study On Zero Value Insulator Heating And Discharge Characteristic Based On The Infrared And Ultraviolet Imaging Method

When the porcelain suspension insulator has internal cracks in normal voltage, the internal of insulator occurs breakdown, forming the zero-value insulator. The discharge and heating characteristics of zero-value insulator is very different from normal insulators. Further, when the insulator string has zero value, the entire insulator string's discharge and heat will change. Currently relatively research for heating and discharge characteristics of zero value insulator and the influence of zero value insulator for insulator strings' heating and discharge characteristics are few. This paper studied heating and discharge characteristics of the zero value insulators based on infrared and ultraviolet imaging method. Works are as follows:This paper researched on the quantization parameter extraction algorithm of UV detector discharge. The ultraviolet image was gradated, segmented, opening and closing operated and a small area eliminated by using digital image processing technology, which achieved discharge characteristic parameter extraction, including spot area, perimeter, major axis and minor axis. And the use of Radon transform projection algorithm get the curve of space discharge intensity along the direction of insulator, to help analyze intensity discharge of more area discharge.This paper used infrared imaging and UV imaging method to research the heating and discharge characteristics of insulator string which has one piece zero value insulator in different salt density and different humidity conditions. Found that in the dry soil, insulator heating had little relationship with salt density. And zero value insulator almost had no temperature, and its temperature was difference between neighboring insulators 1 ~ 3 ? ?. And closer to the high voltage side, the greater impact on the entire insulator string's heat and voltage distribution and vice versa. The infrared detector can effectively detect. When wet was dirt, the temperature of zero value insulator porcelain was same with the normal insulator porcelain that didn't occur discharge. Therefore, when the wet is dirt, infrared detector is not sensitive, but detected by UV discharge insulators found in small salt density, neighboring insulator of the zero value insulator occurred discharge easily. So the zero-value insulator can be qualitatively judged by UV.To verify the accuracy of the experiment, the insulator string of electric field and the temperature field were simulated in different salt density, different humidity and zero values insulator in different locations. The simulation found that when soil was dry, the electric field mainly distributed inside of the insulator. If the zero values insulator was closer to the high voltage side, the impact on the entire insulator string's temperature and voltage distribution and vice versa was greater. When wetted dirt, the electric field distributed on the surface of insulator. And with the salt density increasing, the effect with potential distribution of the whole insulator string was smaller. Also, the zero value insulator and normal insulator substantially had the same temperature. The simulation results were consistent with the experimental results of the analysis.According to the experimental and simulation results analysis, achieved the zero-value insulator diagnosis using a threshold method. And the use of VC ++ was developed zero-value insulator management and diagnostic software based on ultraviolet, infrared detecting.