Análise comparativa de isoladores poliméricos sob defeito externo e poluição a partir do método dos elementos finitos.

Abstract

This work presents an evaluation of the electric field and potential in polymeric insulators under different operating conditions. The conditions considered were: intact isolator, with the presence of external defect and under the effect of pollution. Thus, two 138 kV polymeric insulators were modeled with the aid of a multiphysics simulation software that employs the Finite Element Method.. A thin conductive layer was modeled on the surface of the insulators in order to investigate the influence of pollution on their electrical behavior. The external defect, in turn, is represented by a hole that surrounds the insulator in a 360 ° rotation and deep enough to reach the interface between the sheath and the core. In simulations performed on polluted insulators, it was detected that the insulator has a resistive characteristic, with low intensity electric field peaks. While the analysis of defective isolators showed that the electric field is distorted, the intensity of which is sufficient to cause air ionization and electrical rupture. From the results obtained for each insulator, it was possible to observe the electrical characteristics of the two topologies of polymeric insulators and to verify which topology presents the best electrical performance.