Study On The Contamination Accumulation Characteristics Of Cantilever Composite Insulators In Overhead Contact Lines Under Sandstorm Environment

The sandstorm weather in northwest China has caused multiple insulator pollution flashover accidents,which will lead to overhead contact lines unabling to power normally.As the Insulators' surface area pollution is the premise of flashover,it is quite necessary to carry out an intensive study on the pollution of insulator.This work has been analysed the fouling property of the composite insulator in overhead contact lines under sandstorm environment,by means of building models in software and simulation,and the result can be used as a reference for the cause analysis of the composite insulator flashover in overhead contact lines under sandstorm environment.In this thesis,a wind tunnel simulation model of the composite insulator in overhead contact lines under sandstorm environment is set up in combination with the function of hydrodynamic field and static electric field.The finite element software COMSOL Multiphysics is used to simulate and calculate the surface pressure and the fouling quality of composite insulator of catenary wrist arm in different wind-sand environments,and the results are analyzed.The simulation results show that the surface pressure of insulator increases as the wind speed increases.When the grain size is 10-40 ?m,the fouling quality increases with the wind speed and reaches saturation.When the grain size is 40-60 ?m,and wind speed is at 0-15 m/s;wind speed increases,the fouling quality increases as well;When the wind speed is 15-30 m/s,wind speed increases,the fouling quality will increase to saturation.When the grain size is greater than 60 ?m,the fouling quality decreases as the wind speed increases and reaches saturation.When wind speed slow down and the voltage is 0-80 kV,the surface pressure of the windward and leeward increases with the increase of voltage,and the fouling quality increases as well.When the wind speed getting stronger and the voltage is 0-80 kV,the pressure on the windward and leeward is basically unchanged with the increase of voltage,so does the fouling quality.When the grain size is 10-40 ?m,the surface pressure of the windward and leeward increases with the increase of grain size,and the fouling quality increases as well.When the grain size is 40 to 100 ?m,the pressure on the windward and leeward tends to be stable with the increase of grain size,and the fouling quality's increasing trend slows down and gradually reaches saturation.Increase sand particle concentration,increasing surface pressure and increase quality of fouling.Compared with relevant literature,the results of this simulation is consistent with the general rule of insulator pollution characteristics.However,when the wind speed is low,for those grains in smaller size,it would be more accurate to analyze the insulator pollution characteristics by electrostatic field because of the obvious effect of the electric field force on the change of grains' movement.