Simulation Of Contamination Deposition Characteristicson Composite Insulators In Dirty Fog Environment

In recent years,the haze weather is frequent.When the ambient humidity is high,the haze is easily converted into a high-conductivity fog.In the more polluted areas,the fog conductivity can reach 2000~3000?S/cm.Considering the high conductivity,high salt content and easy deposition,it will greatly increase the salt density of the insulator of the transmission line and threaten the safe operation of the power system.Composite insulators are widely used on transmission lines due to their light weight,high strength and high flashover voltage.Therefore,it is of great practical significance to study the fouling characteristics of composite insulators in a foggy environment.In this thesis,FXBW-110/120-2 composite insulator is taken as the research object.Based on the field-induced motor theory,the insulator simulation model of insulator is established by using COMSOL software to explore the wind speed and droplet size change under the action of no voltage and DC voltage.The average force of the droplets on the surface of the insulator and the collision characteristics of the droplets in different regions of the insulator;the effects of wind speed,droplet size and voltage type on the insulator fouling(ESDD)characteristics were analyzed.The results show that:1)the drag force in the inflow direction is much larger than the electric field force,and the drag force in this direction is the main force for driving the droplet movement;in the axial direction of the insulator,as the particle size of the droplet increases,the electric field force Gradually increase and eventually exceed the fluid drag.2)For different regions of the insulator,the larger the overall wind speed,the smaller the collision coefficient P_E;when there is no voltage,the larger the droplet size,the larger the upper surface P_E,and the smaller the lower surface P_E;when the DC voltage acts,the mist droplets The larger the diameter,the smaller the upper surface P_E,and the larger the lower surface P_E,the presence of electric field force is favorable for the droplet to collide with the lower surface of the insulator.3)Regardless of the voltage applied or not,the whole volume of the insulator increases with the increase of the wind speed in the particle size range,and the wind speed and the amount of dirt are approximately linear.4)When there is no voltage,when the wind speed is constant,the amount of dirt under each droplet size does not change much;when other conditions are the same,the whole volume of the insulator under the action of DC voltage increases with the increase of the particle size of the droplet;5)When there is no voltage,under the action of gravity,the amount of dirt on the upper surface of the insulator is more than that on the lower surface;when it is applied by DC,the amount of dirt on the lower surface of the insulator is more than that of the upper surface.6)When there is no voltage,the amount of dirt is distributed evenly along the insulator skirt;when the DC voltage is applied,the particle size is different(except when the particle size is 1?m),and the amount of dirt is approximately U-shaped along the shed,and The larger the droplet size and the lower the wind speed,the more obvious this U-shaped distribution.