INSULATION PROPERTIES OF A STRING OF 3 UNIT SUSPENSION INSULATORS DEPENDING ON SEA-SALT CONTAMINATION AND SEA-FOG NEAR THE COAST OF PACIFIC OCEAN

输电线路绝缘子的绝缘性能随气象条件和环境条件的变化而变化较大，本文通过对大气盐度的测量，推测了海盐污染的原因。此外，还利用延时录像机观测了海雾的出现趋势。考察了影响海盐污染的因素和海雾的出现趋势，并讨论了海盐污染和海雾对绝缘子绝缘性能的影响。从调查结果可以得出以下结论：(1)泄漏阻值的变化取决于相对湿度的变化，(2)绝缘子漏电阻值的降低是由于100%相对湿度下浓雾天气下绝缘子罩湿表面造成的。(3)当雾密度适合于雾到来前被海盐颗粒污染的湿式漏电棚面时，不通过雨或浓雾冲刷海盐，漏电阻值下降。

The insulation properties of an insulator for the power transmission lines change greatly according to the meteorological conditions and the environmental conditions.In this paper, we guessed the sea salt contamination from the measurement of salinity in the atmosphere. Moreover, the appearance trend of the sea fog was observed by using the time lapse video recorder.We examine factors which influence the sea salt contamination and the appearance trend of the seafog, and discuss the influence of the sea salt contamination and the sea fog on the insulation properties of an insulator.From the results of the investigation the following can be concluded :(1)Variations in Leakage Resistance value depend on variations in relative humidity, which depend on variations in temperature in clear weather.(2)Decreases in Leakage Resistance values are caused by wet surface of insulator sheds produced in dense fog during 100% of relative humidity.(3)When fog density is suited to wet shed surfaces contaminated by sea salt particles before the arrival of the fog, without washing away sea salt through rain or dense fog, the Leakage Resistance values decrease.