Detection of Polymer Insulator Surface Based on the Effects of Tropical Climate Using Partial Discharge Signals Measurement

One important component in the high voltage overhead lines placed on the transmission tower is the insulator. When polymer insulators are installed in tropical climates, there will be two conditions occurs, such as: i) the changes from wet to dry will cause the pollutant particles in the air will attach to the surface of the insulator. This condition will cause the sedimentation on the surface of the insulator; ii) the changes from dry to wet will form a conductive layer that leads to the leakage current flow. The flow of leakage current leads to the formation of dry-band on the surface. The formation of a dry band creates an electric arc or PD and can eventually cause a flashover insulator. Laboratory experiments were carried out at different levels of pollution and RH. PD signals in the form of leakage current flowing to the ground are transformed by HFCT. PD patterns are collected through an innovative PD detection system. PD signals measured in the form of PRPD patterns are evaluated using the concept of equivalent band-width and time-length equivalent to understand the pollution performance of polymer insulators. The width of the frequency field produced from the experiment can be the basic of analysing the severity of the surface pollution of outdoor polymer insulators.