Study On Dynamic Contamination Accumulating Mechanism Of Insulators In Saline Area

Saline-alkali land is widely distributed in China and its soil is rich in salt.After a large amount of salt particles are blown off the ground by the wind and fall on the surface of the insulator,the probability of insulator flashover accidents increases,which greatly affects the safe operation of power lines in saline-alkali areas.Pollution flashover accidents of insulators in China's power system occur from time to time,and the existing anti-pollution flashover methods are slightly insufficient.This article studies the dynamic pollution accumulation characteristics of insulators,and provides a theoretical basis for anti-fouling work.Firstly,the movement process of pollution particles is analyzed by stages,the energy conservation formula is established for the collision process between the contaminated particles and the insulator surface,and the boundary conditions for the adsorption of pollution particles under different conditions are obtained.The factors that affect the adsorption of dirty particles are wind speed,air humidity,and particle size of dirty particles.According to the analysis of the influence of various factors on the movement process,the influence of different factors on the pollution sedimentation rate is obtained.COMSOL software was used to establish a fouling simulation model.The turbulence module and the electric field module were used to simulate the flow field and electric field around the insulator.The particle tracking module was used to calculate the motion trajectory of the foul particles.The pollution accumulation of insulators under different wind speed,pollution concentration,humidity and particle size was calculated.The results show that the pollution amount of insulator surface area increases continuously with the increase of air humidity.With the increase of pollution concentration,the pollution amount of insulator surface area increases continuously.With the increase of wind speed,the pollution amount of insulator surface area first increases and then decreases gradually.With the increase of pollution particle size,the pollution amount of insulator surface area first increases and then decreases.Then,the stress conditions of dirt particles deposited on the surface of the insulator and the scouring force of wind and rain on the dirt particles are studied and analyzed,and the boundary conditions of pollution scour are obtained.The wind scour is mainly the drag force of the wind,and it is calculated that pollution cannot be effectively washed by wind.When rain scours,if its scour force meets the conditions,it can scour the pollution.Collect the experimental data of rainfall scour,select some experimental data,and use MATLAB software to select a suitable model for data fitting,and get the relationship model between the rainfall parameters and the amount of pollution residue.Draw the influence curve of different rainfall parameters on the pollution residue.The results show that the effect of rainfall scour on salt density is greater than gray density.With the increase of rainfall intensity,rainfall time and other parameters,the effect of rainfall scour becomes better,but when it increases to a certain value,the pollution residue will tend to be stable.Finally,according to the influence of weather parameters on the accumulation of pollution,combined with the changes of parameters in different weather conditions,the accumulation rate of insulator in different weather conditions is analyzed.The results show that the pollution accumulation rate of insulator is relatively low in the weather without wind and rain.The rate of pollution accumulation in breezy weather is slightly higher.In light rain and heavy fog weather,the pollution accumulation rate increases further due to the moist air.In strong wind weather,the pollution accumulation rate increases with the increase of the wind speed,and decreases after reaching a certain degree.In heavy rain weather,the residual amount of pollution on the insulator surface decreases with the increase of rainfall intensity,scouring angle and rainfall time.