应用盘面特征识别红外检测盲区的零值绝缘子

依据铁帽特征的零值绝缘子红外检测存在检测盲区,零值绝缘子的漏检将严重威胁电网的安全运行。本文将盘面特征纳入劣化识别判据中,建立了湿污绝缘子串盘面温升求解模型,该模型通过对串中不同位置绝缘子表面干燥带及干燥带电弧等运行状态进行判别,再根据热交换过程中功率平衡求解出盘面温升分布;并提出了以零值绝缘子与相邻绝缘子盘面温差特征来识别红外检测盲区内的零值绝缘子。仿真和试验结果均表明:湿污状态下,零值绝缘子盘面呈现"负温差"特征,且"负温差"程度由表面污秽度、空气湿度和零值绝缘子在串中的位置决定。

Identification of Zero-value Insulators in Infrared Detection Blind Zone Using Disk Characteristics

The detection blind zone exists in the infrared detection of zero-value insulators based on the characteristics of the steel cap,and the leakage detection will seriously threaten the safe operation of power grid.In this paper,the disk characteristics are introduced to the criterion for the identification of deterioration,and a disk temperature rise model for a wet polluted insulator string is established.The operation states,such as the dry surface band of the insulator at different positions in the string and the dry band arc,are adopted in the identification;according to the power equilibrium in the heat exchange process,the distribution of disk temperature rise is obtained;based on the disk temperature difference between the zero-value insulator and the adjacent insulators,the zero-value insulator in the infrared detection blind zone can be identified.Both simulation and experimental results show that in the wet polluted condition,the zero-value insulator disk presents the“negative temperature difference”characteristic,and the difference degree is mainly determined by surface contamination degree,air humidity,and the position of the zero-value insulator in the string.