Study On Transmission Line Insulator String Flash-over Characteristics In Salt Fog Environment

The traditional view about insulator flashover is that insulator flashover is mainly affected by type A pollution,such as surface contamination.This is correct in the inland area.However,for the insulators in coastal areas,flashover accidents still occur when there is limit number of type A pollution on insulator surface.This is because of the impact of type B pollution.At present,the research on the impact of type B pollution on insulator flashover in China is still blank.Therefore,it is necessary to study the influence of salt fog on flashover characteristics,surface contamination and discharge process of insulators.The main contents of this paper are as follows:In order to study the influence of salt fog on AC flashover characteristics of insulator,a lot of artificial simulation of salt fog flashover test is carried out.According to the results of the study,the conclusion is drawn:In salt fog environment,there is a relationship between the flashover voltage of glass insulator string and the surface contamination salt density and salt fog salinity,and the flashover voltage decreases with the increase of salt density and salinity.The conclusion is to establish the quantitative relationship between flashover voltage and fouling salt density and salt spray salinity.In order to study the influence of salt fog on the surface contamination of insulators,this paper innovating the test method,and carrying out the salt density change test in salt spray environment.According to the results of the study,the conclusion is drawn:In the salt fog environment,the salt density of the insulator surface will not be significantly reduced by the salt fog.The surface pollution high salt density is beneficial to the generation of the discharge along the surface,and then reduces the flashover voltage of insulator strings.The conclusion creatively put forward that the influence of salt fog on flashover depends on the influence of surface salt density on flashover voltage.In order to study the effect of salt spray on the AC discharge process of insulators,the occurrence and development of electric arc were recorded and analyzed.According to the results of the study,the conclusion is drawn:In the salt spray environment,the flashover of insulators is mainly surface discharge.However,the electric field distortion caused by salt spray will cause space discharge,and then affect insulator string flashover voltage.It point out that there is space discharge in the discharge of insulators in salt fog environment.At the same time,it creatively put forward the affection of salt fog on flashover,which affects the flashover voltage by triggering the space discharge.In order to study the effect of salt fog on the flashover characteristics of composite insulators and RTV insulators,this paper compares the flashover voltage of the two types of insulators and glass insulators under the same conditions.In the salt fog environment,the insulators with climbing distance and hydrophobicity have better insulation performance than glass insulators.