Electric Field Optimization Of Shed Parameters Of DC Post Composite Insulators

Post insulators play an important part in AC and DC transmission lines, supporting andinsulating power equipment. For a long time, pollution flashover accidents have occurred topost insulators home and abroad, posing a great threat to the safe and stable operation ofpower grid. Researches about how to prevent the pollution flashover accidents and improvepollution flashover performance of post insulators have become more and more urgent in therelated study of post insulators.Artificial contamination test researches show that, the pollution flashover performanceof DC power system is affected by shed parameters of post insulators obviously and could beimproved after the optimization of shed parameters. Artificial contamination test can simulatethe procedure of moistening and flashover development of insulators actually. But in thesame time, it consumes large number of human and material resources.The procedure of pollution flashover is complicated, which is related to the distributionof potential and electric field along the insulators. Via calculation of electric field, theoptimization of grading ring profile has been studied thoroughly and verified by artificialtests. But simulation researches on optimization of shed parameters are rarely seen. Therefore,a systematic study of the potential and electric field distribution of the polluted postcomposite insulators, and optimization of shed parameters have both a very importantacademic meaning and an engineering value.Based on the shed profile optimization result of artificial pollution tests, this paperestablished polluted post insulators by Finite Element Method software ANSYS and studiedthe electric field distribution along polluted insulators influenced by spacing between largesheds and overhang of the sheds. The creepage distance and electric field were put forwardsas the criterion to optimize the parameters of sheds. Finally, advice parameters for follow-upresearches on shed profile optimization of DC post insulators were put forwards.