污秽绝缘子的紫外成像检测

Detecting Contaminated Insulators by the UV Imaging Technology

绝缘子积污是电力系统常见的一种现象,严重时可能引起绝缘子串闪络,导致大面积、长时间的停电事故,现已经成为对电网安全最具威胁的因素之一。目前的检测手段存在固有的缺陷和局限性,如红外检测存在检测盲区,不能检测早期故障。笔者研究了如何用紫外成像法检测绝缘子的绝缘状况,采用固体涂层法模拟线路上的绝缘子串积污,通过导电杆对积污绝缘子串加压,用CoroCAM504紫外成像仪观察其紫外成像图。实验结果表明,紫外光子数的最大值与对应时间段的泄漏电流的最大值有着较好的对应关系。在环境湿度较大,如毛毛雨、雾等天气条件下,用紫外成像仪可检测积污程度在a级以上的绝缘子,这为紫外成像仪在工程中的应用提供了一定的依据。现场应用实例也验证了紫外成像检测的有效性。

Contamination of insulators is a common phenomenon in electric power system,when severe may cause flashover and lead to large area and long time insulator power failure.So the insulator flashover has become one of the most threatening factors for power system safety.The detection methods used now have inherent defects and limitations,such as infrared detection technology has a blind area and can not detect the early failure.This paper studied on how to use UV imaging device to detect insulation status of insulators.The research used solid-layer method to simulate contaminated insulators on line,upraised voltage on insulator string through conductor pole,and used CoroCAM504 ultraviolet imaging camera to observe the UV images of its corona discharge.The results showed that there is a good corresponding relationship between the maximum value of photon number and leakage current.And using ultraviolet imaging device can detect insulators whose contaminated grade is higher than grade a at the high environmental humidity,such as drizzle and brume.The results provided a certain reference for the practical applications of ultraviolet imaging device.The spot example is also proved the validity of the UV imaging detection.