The Effect Of Humidities And Air Pressure In The Growing Of Leak Stream And Flashover On Contiminated Ceramic Isolator

The performance of outdoor insulators influenced by environment condition such as mechanical stress, pollution and electricity stress. Environment condition has many variants. Declining of air density caused the height area from sea level that will reduce the ability of an isolator slowly. The solution as water, fog, dust and other small compounds on the insulator surface might reduce resistance of insulator surface, which will cause the increasing of leakage current that flow on the surface of that isolator. In this paper, we investigated about development of leakage current in a bar porcelain sample that was placed to mining area in tropical area which has height approximate of 4000 m from sea level with specific contaminant in that area. This sample is tested in the chamber that can imitate environment parameter like humidity and air pressure. In polluted and simultaneously humid condition, leakage current on insulator surface will increase and it could lead to flashover. The lower air density in the highland area was reduced the flashover voltage. Flashover voltage will be experience to decline of 5% in 2000m area above sea level. The result from this test is the increasing of air humidity that the bigger the magnitude from the leakage current same with change lower of air pressure. Low air pressure is more influence than the higher air humidity on flashover voltage.

Keywords: Contaminant, air pressure, leakage current, time harmonic distortion (THD), flashover voltage