Research On Influence Factors Of Zero-resistance Insulator Detection Based On Infrared Thermal Image

Flashover accident, the insulator off the string and wire off accident caused byzero-resistance insulator, seriousily threat the safe and stable operation of powersystems.Therefore, a safe and accurate zero-resistance insulator on-line detection isone of the urgent need to solve the key issues of grid security. Infrared thermal imagetechnology is widely used in electrical equipment fault diagnosis and detection. In theview of problems of infrared thermal image detecting zero-resistance insulatorsvulnerable to climate conditions such as temperature, humidity and so on, as well aspollution degree, prone to mistaken detection and undetection, the paper studies thefour aspects of influence factors such as measurement error from the infrared cameraitself, the environmental factors, contamination condition, and the loaction ofzero-resistance insulator and detection methods, in order to understand influencefactors and their influence degree. It is of great significance to improve the accuracyof infrared thermal imaging detection.Firstly, according to the infrared detection easily influenced by multiple factorsand the principle being unclear, the paper analyzes the infrared camera works and theinsulator heating principle, and finds the impact of factors theoretically.And then, through the design of laboratory experiments and field experiments, alarge number of the insulators image under different conditions was got. The paperstudies the four aspects of influence factors such as measurement error from theinfrared camera itself, the environmental factors, contamination condition, andzero-resistance insulator’s loaction and detection methods to analyze the insulatorsimage under different conditions, and uses gray relational theory to analyze theimpact of temperature and humidity on the infrared detection. The results show thathigh precision infrared camera can reduce the impact of infrared temperaturemeasurement; the environment temperature has a certain impact on infrared detection,and infrared detection should not be carried out at a high temperature; relativehumidity has a great impact on infrared detection, and selecting the moderate relativehumidity can improve the accuracy of the infrared detection; pollution degree has acertain impact on infrared detection, and pollution makes infrared detection easier.Finally, the paper takes full advantage of the infrared detection of influencefactors findings, and proposes a zero-resistance insulator detection method based on influence factors analysis and probabilistic neural network. When temperaturecharacteristics of zero-resistance insulator are extracted, the ambient temperature,humidity and pollution degree are introduced. The simulation results show that,compared to other probabilistic neural network, the proposed method has higheraccuracy and quicker speed by analyzing related features mentioned above, and thismethod is suitable for online detection of the zero-resitance insulator.