| Silicone rubber composite insulators are widely used in power transmission and transformation external insulation systems because of their good pollution flashover resistance,and provide a vital role for the safe operation of power systems.However,the operating environment of composite insulators is complex.Due to improper installation and other reasons,composite insulators are affected by corona discharge for a long time,which accelerates the aging of composite insulator materials,resulting in degradation of their insulation performance,which may cause flashover accidents and cause major economic losses.In areas such as the southwest and north,composite insulators are often operated in a haze environment,which may promote the aging of silicone rubber materials.To this end,this article conducted a corona discharge aging test on silicone rubber samples in a haze environment to study the impact of the haze environment on the corona aging process and flashover voltage of silicone rubber samples.This article first uses dust generator and atomizer equipment to simulate haze weather in the laboratory,builds a corona aging test platform,and then formulates test procedures to perform different periods on silicone rubber samples in the haze,salt fog,and haze environments.The corona aging test is carried out in the environment of RH>90%,and the corona aging test is carried out on the surface of the contaminated and clean silicone rubber.Afterward,the aging silicone rubber samples were tested to study the physical and chemical properties of the corona-aged silicone rubber from three aspects: surface morphology,water repellency,and resistivity.Finally,the aging silicone rubber was tested in an artificial spray chamber.Leakage current and flashover voltage,the electrical characteristics of aging silicone rubber are studied.The research results of the physical and chemical properties of aging silicone rubber in this paper show that under the action of corona electric field,tiny particles in the environment will gradually cover the surface of silicone rubber,and dirt will weaken the aging effect of corona discharge on silicone rubber;environmental factors affect silicone rubber.The loss of the water repellency of rubber samples has no obvious effect.In terms of water repellency,the samples aged in salt fog environment recover more slowly than those aged in haze environment and haze environment;100h corona discharge cannot damage the internal insulation of silicone rubber,which is different.The volume resistivity and surface resistivity of the aged samples in the environment is not much different.The leakage current of silicone rubber samples increases with the increase of aging time,and the flashover voltage of aging silicone rubber decreases with the increase of aging time,and the wet flashover voltage is lower than the dry flashover voltage;the surface equivalent salt of silicone rubber in the haze environment The increase in density is one of the reasons for the increase in leakage current and the decrease in flashover voltage.The particulate matter in the haze environment impacts the surface of silicone rubber at high speed under the action of the electric field,and plays a major role in the damage of the silicone rubber surface in the early stage of corona discharge,while the soluble salt in the haze environment coronas the silicone rubber in the middle and late stages.Aging plays a certain role in promoting,and the effect of ammonium sulfate is stronger than that of sodium nitrate. |
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