A Comparative Study of Electric Fields beneath Compact and Non-Compact Transmission Lines

Abstract

This paper presents the charge simulation method (CSM) with complex charges for the computation of electric field distribution under Extra High Voltage (EHV) transmission lines (conventional and compact). Electric field at ground level is becoming one of the most important factors for proper design and safe operation of EHV lines because of its biological effects. The ground is taken into account by the method of images. A single tower transmission line carrying a single circuit with six different configurations is studied and analysed. All the cases have the same degree of compaction (i.e. the ratio of line-to-line voltage/space between the two phases is constant) for the purpose of comparison. It is found that the electric field is reduced by 30-70% for some of the compact designs compared with conventional ones.