Research About Pollution And Electric Field Distribution Characteristics Of XP701 Insulator

Pollution flashover of insulator is one of the main causes of power system safety operation failure,and the deposition of dirty particles on the surface of insulators is a necessary condition for pollution flashover.Therefore,research on the fouling characteristics of insulators can help reveal the law of insulator fouling and reduce pollution flash rate.The natural accumulation of contaminated particles is affected by factors such as insulator type,wind speed,pollution concentration and electrostatic field.The charge of natural polluted particles in the particle flow field of the near transmission line will affect the distribution of the electric field around the insulator,thus changing the movement of the particles.The trajectory affects the fouling of the insulator surface.In this paper,in view of the natural fouling characteristics of XP701 insulators and ZSW-35 insulators,the numerical simulation software COMSOL combined with the wind tunnel experimental system is used to analyze the effects of wind speed,contamination particle size and concentration in the simulation results.In the post-treatment,obtained the relationship curve and ratio between gravity,fluid drag and electric field force of fouling particle near the insulator,and a more reasonable charging way of particle.According to the influence of charged particle on the fouling characteristics and surface electric field of the XP701,the electric field around the XP701 insulator was simulated by COMSOL.The particle size,number,charge-to-mass ratio and electric field distribution were analyzed under the charge.Impact.The results show:When particles close to the insulator,the fluid drag,electric field force and gravity in the horizontal and vertical directions are all of the same order of magnitude.At small wind speeds,the electric field force in the vertical direction is smaller than the fluid drag force and is in the same direction as the gravity.The resultant force of the three forces vertically causes the dirt particles to deposit more on the upper surface of the insulator.For the leeward side,the collection of contamination is mainly caused by the vortex generated by the leeward flow.When the contaminated particles are not charged,the potentials in the single shed are distributed in the form of “M” or “W”.The potential lines in the insulator string are pointed from the middle shed to the ends or infinity,and the potential lines near the middle shed are the most dense.The voltage at both ends is the highest;while the particle size of charged particles is 30?m,the number is 300,and the charge-to-mass ratio is +1.58×10-4C/kg,due to the distortion of electric charge on the electric field,the potential increase of the shed skirt slows down.The potential of the No.2 umbrella skirt is half of the original value,but the high voltageside of the umbrella skirt field is increased to 1.4 times,and the field strength of the lowvoltage side umbrella skirt is even increased to 3 times.The effect of particle size on the electric field around the insulator is relatively simple.As the particle size increases,the charge of the particles increases,further aggravating the electric field distortion around the insulator.When particle size is 50?m,the field strength at the inflection point of the insulator reaches a maximum,The field strength of the high-voltage side is 9 times that of the area where the particles are not charged,local arc is easily produced in this area.