الفهرس 
chapter 1Only 14 pages are availabe for public view
 |  | from | 139 |  |  |
| | | from | 139 | | |
Abstract
The present work introduces a comprehensive investigation on the effect of humidity, dew and rains on the electrical characteristics of the widely used polymeric insulating materials. Experiments on breakdown voltage, inception voltage and leakage current variation have been done under different contaminant DROPs for different polymeric materials such as: Silicon rubber, Epoxy resin, Polyvinyl – Chloride and Bakelite. Thereby factors affecting the behavior of polymeric insulators such as different directions of the applied electric stress, number of DROPlets, volume of DROPlets, different DROPlet positions, different electrolyte bymass, different contaminants solutions and different polymeric insulators with different surface roughness and hyDROPhobicity have been studied. The impact of different types of fillers on the behavior of polymeric material has been also investigated.
As a theoretical investigation, the electric field distribution over both dry and wet conditions has been calculated when normal and tangential electric stresses have been applied. The impact of previously indicated factors on the electric field distribution has been also determined. The validity of the results has been checked by comparing both theoretical and experimental results.