Abstract—Electrical insulators in 22kV Distribution System of the Provincial Electricity Authority (PEA) is mostly porcelain insulator types that consist of line post insulators in the serious pollution area. The insulators of distribution system will be polluted by industrial contaminants, salt fog or natural dust. In the records of PEA shows that pollution flashover is one of the main natural calamities harming and affecting the voltage stability and reliability of distribution system. This paper to study and compares the test results obtained from artificial pollution tests according to IEC 60507 with line post and pin post type insulators of medium system under same test conditions. The salt fog test results indicate that the pollution flashover performance of pin post insulator is less than to 65 percent of wet power frequency withstand voltage at equivalent salt deposit density (ESDD) = 0.5mg/cm² and the leakage current (LC) of line post insulator increased to 10.8mA at ESDD = 0.5mg/cm² at nominal voltage. In the experiment indicate that AC pollution flashover performance of pin post insulator has better than line post insulator in the serious pollution area. This data will be useful to be guideline for solving problems and reducing power loss from leakage current on the surface of the insulators as a result of surface dirt and pollution. Moreover, it will be useful to select or design suitable insulators for using in places with salt conditions, high rainfall, high wind speeds and high humidity. 
 

Index Terms—pollution flashover, electrical performance, electrical insulators

Cite: Peerapol Jirapong and Wichet Thipprasert, "Electrical Performances of Line Post Insulators in 22kV Distribution System," International Journal of Electronics and Electrical Engineering, Vol. 4, No. 2, pp. 140-145, April 2016. doi: 10.18178/ijeee.4.2.140-145