Safety Assessment of Live Working on 500kV V-type Composite Insulator Transmission Line with Conductive Defect

The structures of the composite insulators are different from those of the ceramic insulators and the glass insulators, and the safety parameters of the live working on the composite insulator transmission lines are also different. In this paper, the length parameters of the conductive defects for the live working safety on the 500kV V-type composite insulator transmission line were given through the insulator tests. Compared with the ceramic insulators and the glass insulators, the defective composite insulators are difficult to find out, since the defects usually exist in the interior of the insulators. The electric field distribution characteristics of the insulator strings can be directly applied to the field test of the defective composite insulators. The electromagnetic models 500kV AC transmission line V-type composite insulator strings with the internal conductive defects were established based on the finite element method in this paper. The influences of the length and position of the defects on the electric field distribution of the insulators were analyzed. The calculation results of the electric field distribution can be used as the reference for the accurate measurement of the composite insulators with the conductive defects, and this can ensure the safety of the live working.