Using ultraviolet imaging method to detect the external insulation faults of electric device

Ultraviolet Imager is a new type instrument for electric devices fault detection, which has small volume, light weight and is convenient for carrying and recording. It can help the security inspectors to pay attention and find out some early faults of electric devices, so that can avoid heavy accidents of power grid. However, at present this kind of instrument is not widely used in the power system and its functions need to be more studied. This paper does the investigations on some common external insulation faults of electric devices, such as the breakage, zero-value and contaminated insulator or insulation pole, loose equalizer ring, stream broken of electric transmission line and so on. By the CoroCAM504 UV Imager it gains a number of UV images and related parameters such as the UV photon number and discharge site. The results of the experiments and spot detecting show that, the UV method can do valid detection on the early external insulation faults of electric devices under the certain conditions. At the same time, the paper also gives out some guidelines on how to use the UV Imager properly.