Simulation Study On The Effect Of Particle Charge On Pollution Accumulation Characteristics Of Insulator

Particles will charge in the ion field on the near-transmission line which will affect the distribution of the electric field around the insulator.Changed electric field will change the trajectory of the particles and affect the pollution accumulation of the insulator surface.Therefore,it is necessary to study the influence of particle charge on insulator pollution accumulation characteristics and electric field along the surface.In this paper,the main charge mechanisms of contaminating particles are summarized.COMSOL is used to simulate the pollution accumulation characteristics of porcelain three-umbrella and composite insulators under the different charging modes under wind tunnel test.The simulation results are compared with the experimental results.The reasonableness of the numerical simulation method is analyzed,and the relative reasonable charging way of particles is explored.In particles relatively reasonable charging way,the natural pollution accumulation characteristics of the porcelain three umbrella insulator in 110 kV AC and AC transmission lines in weak winds and breeze were simulated numerically.The relative sizes of drag force,gravity and electric field force are compared.The effects of wind speed,particle diameter,and pollution concentration on the natural pollution accumulation characteristics are analyzed.The electric field along porcelain three-umbrella insulator in clean and polluted environment is numerically simulated.The effects of particle diameter,quantity,charge-to-mass ratio,polarity on the electric field along the surface of charged particles are investigated.The results show that:(1)The numerical simulation method adopted in this paper is reasonable,the particle "proportional" charging way is more reasonable.(2)Under the action of DC and AC voltage,with the increase of wind speed,the pollution accumulation increase first and then decrease.With the increase of pollution concentration,the pollution accumulation increase and the growth rate slow down,the former is faster than the latter.(3)In the weak wind(0.5~2m/s),under the action of DC voltage,the pollution accumulation increases with the increase of particle diameter.Under the action of AC voltage,the pollution accumulation increases first and then decreases with the increase of particle diameter.In the breeze(3~5m/s),under DC and AC voltage,the pollution accumulation increases with the increase of particle diameter.(4)The geometric shape of umbrella skirt can influence potential and electric field distribution of the insulator surface.The potential and electric field strength along the surface curves of each umbrella skirt have different similarities inclean and polluted environments.(5)The maximum value of electric field strength along the surface occurs at the junction of the cast iron,air and porcelain,and the main special inflection points in clean and polluted environments.(6)The direction of the field strength vector is different in the clean and polluted environment,the former from the high voltage end umbrella skirt to the low voltage side;the latter(particle size is large enough)when charge-to-mass ratio is positive from the middle umbrella skirt to the high or low voltage side,when charge-to-mass ratio is negative,the opposite is true.(7)The maximum value of field strength along the surface of each umbrella skirt increases with the increase of particle diameter,number and the absolute value of the charge-to-mass ratio.(8)The field strength maximum value in polluted environment can up to 9 to 70 times in the clean environment.