Development Of Solar-blind Ultraviolet Imager And Its Application In Pollution Detection Of Insulators

Insulators of transmission line are one of greatly used electrical components.The surface of the insulators running outdoors will deposit filth because of factors such as air pollution.the insulation strength of polluted insulators will reduce under wet conditions,even cause surface discharge and emit ultraviolet signal,the more serious the pollution phenomenon is more obvious.The intensity of ultraviolet signal is closely related to the surface discharge of insulators.It can characterize the intensity of surface discharge on insulator,so that it can estimate the running state and contamination level of insulators.UV imager is a device for UV detection.The current UV imagers are all produced abroad.The output of ultraviolet images is all visible and ultraviolet fusion video,and the ultraviolet image has no gray value characteristics.In this paper,we have developed a set of ultraviolet imaging hardware and software system with output image whitch has gray value characteristics,and integrated information such as temperature,humidity,air pressure and observation distance.Based on that,we studied the discharge of polluted insulators and evaluated the contamination level of insulators.The completion of the specific work of this article is as follows.The optical system of ultraviolet imaging system is established,and the non common optical axis structure of ultraviolet and visible light is built.The structure and performance parameters of the ICCD imaging system,UV spectrum characteristics about ultraviolet imager system is presented.The power supply part of the UV imager is designed,generating various voltages to supply power to each module,realizing system power management function,and protecting the system from power failure.A temperature and humidity and pressure collection system based on MCU is designed.The data of temperature and humidity,air pressure and laser rangefinder are collected by microcomputer,in addition the gain and gate of ultraviolet imager is controlled by MCU serial port.The MCU driver is written to realize the management of the power supply and the temperature control of the instrument,and to complete the data interaction between the MCU and the industrial control machine.The software system of ultraviolet imager is designed.The SDK driver package is used to collect ultraviolet video and visible video.Correction of ultraviolet and visible video is corrected by migration correction coefficient,and fusion of ultraviolet and visible videos is applied to locate the electrical equipment accurately.The functions of preview,photo and video of ultraviolet and visible video are realized by software.In the artificial climate room,the characteristics of the UV image parameters of seven XWP7-160 insulator strings under different contamination conditions are studied.Clustering and GraphCuts algorithm are used to extract every feature of the UV image,and calculate the area of the UV equivalent spot based on the gray value.,the area of the main spot,the perimeter,the long axis and the short axis information.The mathematical relationship between the area of the equivalent UV spot and the observed distance is obtained by studying the characteristics of the area of the equivalent UV spot with the variation of the observed distance.The characteristics of UV image parameters of insulator contaminant discharge based on the equivalent beam area,main spot area,main spot,perimeter,long axis and short axis of the main spot as the evaluation index,constructing the projection pursuit model,obtained by calculating the optimal projection direction,and of the insulator contamination degree make a decision evaluation.