LONG-RANGE TRANSPORTED POLLUTANTS AND CONDUCTIVITY OF ATMOSPHERIC ICEON INSULATORS

Internationally comprehensive studies have been performed to analyze t he effect of clean or contaminated snow and ice accretions on high vol tage insulators. Our experience with transmission lines in inland moun tainous areas reveals a substantial contribution of pollution from ant hropogenic (man made) contaminants. One observation of a flashover cas e with thin rime ice layers in contrast to the many cases with thicker accretions without similar failures, led to the question of the role of the ion content of the ice. 55 ice samples are analysed and the con tributions to the conductivity from natural (sea salt) and man made io ns (sulphur and nitrogen components) are found. It is shown that long range transported anthropogenic ions contributed to more than 50% of t he conductivity in 33 of the 55 cases, and in 21 cases the contributio n was more than 80%.