Calculation of electric field and partial discharge activity reduction for covered conductor/high voltage insulator systems

- A proposed covered conductor design to reduce partial discharge activity for covered conductor/insulator system is presented.
- Electric field calculations, using FEM, for the conventional and proposed covered conductor designs are presented.
- Partial discharge inception (PDIV) and leakage current are measured at different conditions.
- A comparison between polyethylene and porcelain insulators with covered conductor systems is performed.

In this paper, a proposed covered conductor (CC) sheath design is presented. The proposed design is theoretically evaluated based on calculations of electric field strength at different regions using finite element analysis. These calculations are carried out considering the conventional as well as the proposed CC designs. The evaluation is done concerning two different insulator types such as porcelain and polyethylene insulators. The proposed design aims at reducing the electric field strength at sheath/high voltage insulator interface as well as at the dry bands formed over the wet polluted or ice covered insulator. Therefore, activity reduction in partial discharge at the sheath surface and dry band arcing over the high voltage insulator surface can be achieved. The proposed design is experimentally evaluated based on partial discharge inception voltage (PDIV) measurements considering dry and polluted conditions. Also, the experimental evaluation is carried out considering leakage current measurements under wet polluted condition. The obtained results either theoretical or experimental give an evidence for an efficient proposed design in electric field, partial discharge, and dry band arcing reduction for CC/insulator system.

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