Calculation of the electric field distribution on ADSS fiber optic Ccable

Abstract

The electric field is responsible for starting an arc across the dry band formed on ADSS (All Dielectric Self-Supporting) fiber optic cable installed below high voltage transmission line and may favor its extension along the electrolytic surface. Knowledge of electric field distribution can deepen the understanding of the behavior of dry-band arcing phenomena on ADSS fiber optic cable. In this paper, the electric field distribution is calculated and compared. It is found that the dry-band arcing is initiated by cascaded breakdown of the dry band. The models to implement the calculation of electric field with and without presence of arc are proposed. When there is arc, the authors proposed a new model, in which the arc column is modeled as space charge, to implement the calculation. The methods for calculating the necessary parameters are proposed. The criteria for the arc to extend along the electrolyte surface is discussed and it is concluded that electric field is not high enough to have significant effect on the expansion. The field calculation is implemented using boundary element method in commercial software Coulomb/spl reg/.