Insulation Characteristics of Polymer insulatois due to sea-salt contamination and snow accietion with seasonal wind in the coast of Sea of Japan in winter

绝缘子的现场试验场建在日本海海岸附近的本滨市Obia-Cho Rumoi区。在这个试验场，几种型号和材料的绝缘子已经经受了海盐和雪的侵蚀。从考点到海岸的直接距离约为80米，地面平坦。试件绝缘子悬挂在海拔10米处。用直流泄漏电阻(表面电阻)测量了样品绝缘子的绝缘，并收集了气象数据。聚合物绝缘试件材料为硅橡胶、三元乙丙橡胶和EVA三种材料。并将几种瓷绝缘子与聚合物绝缘子进行了比较。连续2年每月测定盐沉积密度和不溶沉积密度。海盐和积雪共同作用下绝缘子的绝缘性能下降，这是由于沿海强风吹来的海盐沉积，以及风吹雪花使绝缘子表面湿润所致。通过对试验场瓷质悬式绝缘子的绝缘特性与距海岸750m内陆变电站瓷质悬式绝缘子绝缘特性的对比，可以看出海岸风对试验场绝缘特性的影响很大。硅油在硅橡胶表面外的硅橡胶绝缘子的绝缘特性与蜡在EVA表面外的EVA绝缘子的绝缘特性不同。2002年3~4月亚洲粉尘的沉积情况表明，硅橡胶绝缘子的沉积由于表面的油污淋洗效果较差而持续了几个月，而沉积在瓷绝缘子上的亚洲粉尘很容易被雨水冲刷掉。

The field test site for insulators was constructed near the coast of the Sea of Japan, in Motohama Onishika Obira-Cho Rumoi-district. Several types and material insulators have been subjected to sea-salt and snow accietion in this test site. The distance from the test site to coast is about 80m directly, and the ground surface is flat. The specimen insulators were hanged at 10m above the sea-level. The insulation of specimen insulators was measured as dc leakage resistance (surface resistance) and also weather data were collected. The materials for polymer insulator specimen were the three kind of materials, silicone rubber, EPDM and EVA. The several types of porcelain insulators were also used for the comparison with polymer insulators. The measurement for the salt deposit density and the non-soluble deposit density had been made each month for 2 years. The insulation characteristics under the combination of sea-salt and snow accretion decreases due to the deposition of sea-salt with strong wind from coast, and also due to the wet situation on the surface of insulators produced by the snow flakes blew by wind. It was seen that the wind from coast affected strongly the insulation characteristics in the test site, in the comparison the insulation characteristics of a porcelain suspension insulator in the test site with that in the substation from 750m inland from coast. The insulation characteristics of silicone rubber insulator which the silicone oil is out of the silicone rubber surface was different from that of EVA which the wax is out of the EVA surface. The deposition situation of Asian Dust from March to April 2002 shows that the deposition for the silicone rubber insulators remained for several months because of the low wash out effect by rain due to the oil on the surface, while the Asian Dust deposited on the porcelain insulators of which the type is like a polymer insulators was washed out easily by rain.