Research On Pollution And Monitoring Method Of DC Insulator Based On Gas-solid Two-phase Flow

China's direct current transmission is developing rapidly,and the insulators in the case of direct current transmission are seriously polluted,which may cause pollution flashover,which is one of the hidden dangers of safe operation of power grids.The flashover of the edge is closely related to the insulation of the insulator and the environmental conditions.By studying the fouling of the insulator under DC conditions and the contamination accumulation characteristics of the insulator surface,and developing the online monitoring device in combination with the development of the insulator flashover,it can be It is of great significance to prevent flashover accidents of insulators,monitor the electrical performance of insulators and provide timely reference for the treatment of contaminated insulators.Aiming at the accumulation distribution law of the surface of the DC insulator,this paper uses a model based on the coupling of the Euler-Lagrangian model and the electrostatic field model in the gas-solid two-phase flow to calculate the uneven contamination of the different sheds of the insulator.The effects of different factors on the pollution situation were discussed.By studying the relationship between flashover and leakage current in the case of contamination,the insulator contamination monitoring device was designed and verified by experiments.The main innovations of this paper are as follows:Aiming at the current research on the pollution accumulation characteristics of charged insulators,a coupling model based on the Euler-Lagrangian model and the electrostatic field model is established,and the uneven product of the insulator is calculated.In the case of pollution,the influence of different factors on the distribution law of pollution is discussed,and the feasibility of the model is verified by actual measurement.The characterization relationship of leakage current to pollution amount is designed.Established a flashover discharge model for insulators.The leakage current characteristics of insulators at different stages of flashover development are studied,which provides feasibility for monitoring the contamination of insulators.The leakage monitoring device based on leakage current is designed.The trend of leakage current of insulators under different humidity,salt density and gray density is measured and analyzed,which provides a reference for on-line monitoring of insulators.