Research On State Evaluation Of Insulators Based On Ultraviolet Pulse Detection

Insulator plays an important role in transmission system,whose pollution state is related to the stability of the power grid.Regional accidents of insulators flashover can lower the success rate of reclosing,which will lead to a greater area of power outage and severe economic and property losses.In order to avoid this situation,the operating status of the insulator needs to be monitored constantly to determine its contamination status,so that corresponding measures can be taken before the accident.Therefore,in this paper,UV pulse detection system is designed to monitor the contamination status of insulators,and research the relationship between their contamination parameters and UV pulses.Firstly,the ultraviolet pulse detection system was designed,including the front-end detection system,signal transmission and host computer processing center.Among them,the UV pulse sensor adopts the day-blind UV phototube for design,which can effectively block the interference of sunlight and other ultraviolet light.And the performance of the UV pulse sensor was tested.The results showed that the UV pulse frequency increases with the increase of the discharge intensity,it was found that it can be used for the discharge of insulators.Secondly,in the artificial fog chamber environment,the discharge simulation test of the pollution insulator was carried out.The UV pulse detection device was used to measure the number of ultraviolet pulses under different contamination distributions,salt densities,and ambient humidity,at different AC voltage and DC voltage,respectively.At the same time,leakage current of these insulators are used as a reference.Through the experiment,it is found that:Under the AC voltage,there are differences in the number of UV pulses of different pollution distribution insulators.The number of UV pulses increases with the salt density,and the number of UV pulses increases first and then decreases with increasing humidity.The difference between the number of UV pulses of insulators under different contamination conditions is not obvious,and is affected by the applied voltage and air humidity,which leads to a detection accuracy that is not as good as the leakage current method.Under the DC voltage,there are obvious differences in the number of UV pulses of different pollution distribution insulators.With the increase of salt density,the number of UV pulses increases,and the number of UV pulses increases with the increase of humidity.The difference between UV pulses of insulators in different contamination states is obvious,and the UV pulse method and the leakage current method have the same detection result,which shows that the UV pulse method can be used for the non-contact detection and evaluation of DC insulator contamination status.