Research On Optimization Of Umbrella Skirt For EHV Composite Insulating Sleeve Based On Rain-flashover Characteristics

Pillar insulators play an irreplaceable important role in AC/DC transmission projects.They are insulating pillars supporting busbar of high voltage distribution devices and live part of high voltage electrical equipment,and have important functions of support and insulation.Through relevant research,it can be concluded that optimizing the relevant parameters of the umbrella skirt of the pillar insulator can effectively improve the ability of rain flashover resistance of insulators and ensure the safety and stability of transmission lines.However,at present,most of the research on the parameters of the pillar insulator is aimed at the ceramic pillar insulator and the line suspension insulator.The research on the umbrella skirt structure of the composite pillar insulator is rare.Therefore,in order to ensure the stability of the transmission line and improve the power supply efficiency,it is obvious to optimize the umbrella skirt of the composite pillar insulator.This is particularly necessary.In this paper,the finite element simulation method is used to simulate and analyze the electric field distribution of composite insulated bushing of HVDC equipment,and to optimize the umbrella skirt of composite insulated bushing.The main contents and contributions of this paper are as follows:1.Taking the composite insulated bushing of 500 kV HVDC equipment as the research object,the geometric model of composite insulated bushing was established in COMSOL finite element simulation software,and the electric field distribution of composite insulated bushing in dry environment was simulated.The results were used as the criterion for subsequent rain flashover analysis.2.The electric field distribution of composite insulating bushing in rainyand fog environment is simulated,and the simulation results of electric field distribution are compared with those of composite insulating bushing in dry environment.3.The effects of different rainwater duty ratio,rainwater velocity,raindrop size,umbrella skirt diameter ratio and umbrella skirt unit structure height on the electric field distribution of composite insulating sleeve under rainy and fog environment are studied.The parameters of umbrella skirt diameter ratio and umbrella skirt unit structure height are optimized to obtain composite insulating sleeve.The optimum parameters of umbrella skirt structure design.In summary,the electric field distribution of composite insulating sleeve and the optimization of umbrella skirt structure parameters are studied in this paper.Through the simulation calculation of electric field distribution of composite insulating sleeve under dry and rainy fog conditions and the study of the influence of different parameters on electric field distribution of composite insulating sleeve,it is proposed that the electric field distribution characteristics of composite insulating sleeve are better.The parameters of umbrella skirt can improve the rain flashover resistance of UHV composite insulating bushing.