Particle size distribution characteristics of naturally polluted insulators under the fog-haze environment

Difference of contamination particle size distribution on insulator surface can result in difference in water absorption ability of pollution layer, and then affect conductivity of pollution layer and flashover characteristic of insulator. To study particle size distribution characteristics of contamination of naturally polluted insulators under fog-haze environment, SEM (scanning electron microscope) and image binary software were utilized for statistics of contamination particle size of four kinds of insulators under AC, DC voltage stress, and uncharged condition. The experimental results indicate that contamination particle size distribution of insulators under fog-haze environment obeys lognormal distribution, and 90% of contamination particles are less than 20 μm; Contamination particle size distributions in AC, DC, and uncharged states are different, in which the average contamination particle under DC voltage is the smallest, and the average contamination particle under AC voltage is the most coarse; Average contamination particle of the upper surfaces is coarser than that of lower surfaces; Contamination particle of porcelain insulators and glass insulators are smaller than that of composite insulators. Further analysis shows differences in contamination particle size distribution of difference surfaces, insulator types under difference electrical field, and these diversities are caused by electric field force, gravity on pollution particles, and insulator material. ©, 2014, Science Press. All right reserved.