Design and Evaluation of Insulating Cover in Overhead Distribution Lines

Abstract

In relation to faults in overhead distribution lines due to the contact of animals, trees and etc., the authors have investigated the process of impulse breakdown of covered conductors in contact with bird nests. As a result, it was found that lightning surges lower than the operation voltage of arrestors cause the breakdown. In the distribution lines, prefab insulating covers are employed to protect the conductors from the contact problems. However, the reliability has not been found clearly. In the present study, the authors investigated the design and evaluation of the insulating covers. Then the degradation of conductor covers and the prefab insulating covers and the lightning surges lower than the operation voltage of arrestors were taken into account.