Study On Pollution Flashover Prediction And Operation Of Catenary Insulator In Saline-Alkali Area

As the most common and efficient transportation mode in China,railway transportation plays an irreplaceable role in promoting national economic development and ensuring people's livelihood.Insulators are an important part of the contact network,and their insulation performance is directly related to the normal operation of the entire railway transportation system.The saline-alkali region of Xinjiang belongs to a typical arid sand-dust climate,and there are a large number of salt lakes in the territory.The climate features of drought and frequent sandstorm make the surface of insulator accumulate a lot of saline-alkali pollution in a short time,resulting in frequent pollution flashover accidents.Because the climatic characteristics and pollution characteristics of saline-alkali region are obviously different from those of general inland areas,this paper analyzes the pollution characteristics of insulators by using the meteorological data of saline-alkali region,and studies the prediction and prevention techniques of pollution flashover in this region.The main research contents are as follows.?1?Based on the meteorological data of the research area,the pollution characteristics of the insulator are analyzed to obtain the parameters characterizing the pollution degree.The total amount of accumulated pollution is calculated by the pollution amount formula,and the real-time content of each pollution component is obtained in combination with the characterization parameters of the pollution characteristics.?2?Because of the slight solubility of CaSO₄,the true value of salt density is different from the measured value,so the effect of different pollution components on the solubility of CaSO₄ is analyzed.The solubility model of CaSO₄ was established by thermodynamic equilibrium theory and Pitzer electrolyte solution theory.The surface water conductivity is obtained by using the model of saturated water content of insulator and the conductivity calculation model,and the correction values of ESDD?Equivalent Salt Deposit Density?and NSDD?Non-Soluble Deposit Density?are obtained according to the relevant definition.Substitute the correction values of ESDD and NSDD into the calculation formula of flashover voltage to obtain the predicted value of flashover voltage,set the pollution parameters according to the pollution characteristics of the salt-alkali area,and conduct manual pollution experiments on a single XP-160 insulator.?3?The maximum withstand voltage of the insulator is obtained by combining the unified specific creepage distance and the creepage distance of the insulator,and the pollution flashover warning value is set 10%higher than the maximum withstand voltage.Determine the maintenance measures by comparing the predicted value and the warning value.Combining insulator monitoring technology and pollution flashover prevention measures,a pollution flashover prevention plan for contact network insulators in saline-alkali areas is proposed.Research indicates:The total amount of soluble pollution in saline-alkali sand and dust areas is higher than that of the general inland areas,and the soluble components and proportions in different areas are obviously different.The pollution components are mainly CaSO₄ and NaCl,and the other components can affect flashover voltage by inhibiting or promoting the solubility of CaSO₄ in addition to their own conductivity,and their influence on flashover voltage should not be ignored.The error between the predicted data and the test data is within 6%,which verifies the accuracy of the calculation model.The research results can provide a reference for the operation and maintenance of insulators in saline-alkali areas.