Research And Development On The Intelligen Detection System Of Deteriorated Insulator Based On Infrared Thermal Image

Insulator are important power equipment,which are widely used in substations and transmission lines.The insulator running will result in insulation performance degradation due to due to long-term exposure to electric and mechanical stress and in complex environments.A low zero value insulator,i.e.insulator deterioration,occur.The existence of deteriorated insulators will seriously threaten operation of power system.Therefore,insulator state detection is essential;however,the current detection method has the advantages of large workload,poor safety and low efficiency.Infrared thermographic detection of degraded insulators has become the latest research direction,but there are still many problems such as low accuracy,environmental factors.Therefore,this paper is aimed at the existing problems,and research on the infrared detection of porcelain insulators from the following aspects:1.This paper firstly expounds the rule of law of infrared imaging infrared radiation heating objects and insulator operating state of heating,and establish insulator heating model,calculate the voltage distribution of insulator string and temperature rise estimation of iron cap by simulation with electric network method,and briefly analyze the blind area of infrared detection of insulator.2.A series of indoor simulation tests were carried out to study the infrared deterioration characteristics of insulator strings.The tests included:the heating rule and temperature rise characteristics of normal insulator string iron cap and disk surface,and the influence of the resistance value,deterioration position and environmental humidity of deteriorated insulator on the heating rule and temperature rise characteristics of insulator string.The test results show that the deterioration insulator can be diagnosed by the temperature rise curve of the iron cap of insulator string,but there is a detection blind area.by changing the environmental humidity,the surface of the deteriorated insulator presents a strong deterioration characteristic law,and the problem of detection blind area can be effectively solved according to the characteristic law.3.Proposing a method for dividing the area of insulator disk and steel cap preprocessing the infrared image by graying,median filtering,binarization and morphological processing;Extracting a feature point set in the binary image of the insulator by utilizing skeletonization;Correcting that inclination of the insulator string by Hough transform on the characteristic point set;And then filtering the interference area to complete the final positioning of the iron cap and the disk surface of the insulator string.4.According to the theory of the second chapter and the analysis of the test results of the third chapter,a reference temperature characteristic method based on iron cap and disk surface is proposed to diagnose the deteriorated insulator.The method reduces the missed detection rate for the infrared detection of degraded insulators,and has good popularizarion value in the electic power industry.5.An intelligent detection system of degraded insulator based on infrared thermal image is developed.The system includes five modules:infrared image processing,intelligent identification of degraded insulator,data mining,system management and detection results,and includes two working modes of off-line analysis and on-line analysis of infrared detection of insulator.The research results of this paper provide a more efficient and safer solution for the detection of degraded insulators.compared with the traditional detection methods,it has higher engineering application value and better economic benefit.