Numerical analysis of electric-field distribution around composite insulator and head of transmission tower

In this paper, the electric-field distribution around the composite insulators and the heads of transmission towers is calculated by a model coupling the indirect boundary-element method to the moment method. The heterogeneous media, such as the composite insulators and the filament metal structures such as the transmission towers and the transmission lines, are considered altogether. The method can take into account not only the permittivity but also the resistivity of the media by using the complex resistivity in the frequency domain. The electric-field distribution around a three-phase 330-kV transmission tower with composite insulators was analyzed. The electric fields on the surfaces of the grading rings and the phase subconductors and at the ends of the composite insulators are analyzed. Both the method and the results are useful for the design of high-voltage transmission lines.