A simulation method for winter pollution contamination of HV insulators

This paper presents a novel method to improve simulation of the road salt deposit process on energized high voltage insulators under winter conditions. A pollution generator system prototype was especially designed to produce an external mixing of dry solid contaminants (kaolin powder) with supercooled atomized brine droplets. The formed pollutant particles are transported by air flow, which is produced by a speed variable fan, and then settle on the energized specimen insulator surface which is installed at a specific distance of the pollution generator nozzle. The pollution accumulation process took place inside a climate chamber at -5°C. At the end of each ten-minute exposure, specimen insulators were removed for ESDD measurement according to the IEC 60815 standard. No pre-treatment of the insulator surface is needed and contrary to most of the other contamination methods, it enables study of the rate of increase of ESDD with wind speed and insulator profile under winter conditions. The combined effect of wind speed and dielectrophoretic force was also investigated using a 45-kV ac variable voltage source.