Air Pollution Influences on 150 kV Transmission Insulators Performance

Insulator is one of high voltage equipment in power system transmission which separates high voltage part (conductor) and grounded structure (transmission tower). Most outdoor high voltage insulator installed in Indonesia were made of porcelain with certain electric property such as surface conductivity, Basic Insulation Level (BIL) value, and wet/dry flashover voltage. Therefore, the surface of the insulator must be kept clean during operation period to maintain the electric property. Higher industrial development gives higher environment pollution exposure toward insulator installed nearby the industrial area. This paper described the effect of industrial pollution exposure toward the breakdown of the porcelain insulator through Hardness testing, Scanning Electron Microscopy (SEM) testing, and Ambient air quality testing. Also, the recommendation for maintenance insulator in industrial area has been proposed. Ambient air quality result showed that very high Total Suspended Material (TSP) in the environment where the insulator installed. This pollutant is then recognized as iron material and the SEM result showed that this pollutant stick to the surface of the damaged insulator. Iron pollution exposure created conductive layer on the surface of the insulator that decrease the insulation capability of the insulator. Therefore, the insulator would be breakdown due to the flow of power arc under overvoltage stress during lightning strike. For insulator located in industrial area, it's recommended to perform frequent cleaning by using appropriate method as stated in standard.