The Effect of Voltage Polarity on Ice Accretions on Short String Insulators

Abstract

The present study investigated the effect of voltage polarity on ice deposits accumulated on a short-string of porcelain insulators from 85 μm supercooled droplets in a cold room maintained at a temperature of −12°C. The air velocity and the liquid water content were 3.3 m/s and 2.0 g/m3 , respectively. Under these growth conditions, the type of ice accretion was hard rime with a density of 0.87 g/cm3 and the highest probability of flashover occurrence. With an applied voltage of 15 kV per insulator unit, corresponding to the operational voltage in service, there were no major changes in weight, density or the texture of the ice grown on the surface of the insulators.