الفهرس | Only 14 pages are availabe for public view |
Abstract The aim of this work was, fustly, to investigate the performance of the high-voltage insulators which are installed in polluted areas, to analyze and calculate the electrostatic effects on the maintenance-work team under transmission line as well as on the insulator surface itself. The second purpose was to fmd out an effective method for the cleaning process of such insulators to improve the insulator performance in the different polluted areas and to reduce the flashover-occurence rate. 1- The effect of electrostatic field on the workers under the livetransmission line is investigated. The charge simulation technique is used to calculate the field strength around the object under line at different heights and different lateral distances from the center phase line. 2- The charging current through the human body under the line has been calculated at different simulation methods. The fust simulation of the human body was done by a cylinder and the second one by three spheres with different diameters. The effect of object dimensions and transmission-line ” configurations on the charging current has been considered. 3- A complete computerized model for simulating the high-voltage polluted insulator has been carried out. This model clears the relation between the contamination parameters as well as the insulator data and the temperature distribution on the insulator surface and the flashover phenomena. It deals with practical data of different insulator types and various pollution conditions (uniform and nonuniform pollution layer). By the aid of this model, it can be concluded that the temperature distribution on the insulator surface increases randomly and it is higher near the insulator pin in the case of nonuniform pollution layer. Furthermore, the flashover phenomena have. |