Calculation of electric fields underneath and on conductor surfaces of ultra high voltage transmission lines

The aim of this paper is to calculate the electric fields produced by ultra-high voltage transmission lines. Two transmission lines of different configurations were modeled and simulated. The first line is an 800 kV, flat configuration, six bundles and single circuit in South Africa. The second line is 1100 kV, double circuit, eight bundles, in Japan. The charge simulation technique (CST) is used for calculating the electric field at one meter height underneath these lines. COMSOL computer program is used for electric field calculation at the surface of sub-conductors of for all mentioned configurations. The maximum electric field underneath the lines is 1.9 and 2.1 kVm^-1 for the 800, and 1100 kV lines respectively. The effect of the phase sequence on the electric field for the double circuit transmission line is also studied and presented in this work. The average crest values of electric field at the sub-conductors surface for 800 kV line are 20.69, 23.87 and 20.59 kVcm^-1 for phase A, B and C respectively against 22.79, 27.19 and 20.51 kVcm^-1 for circuit one and 22.68, 27.55 and 20.35 kVcm^-1 for circuit two of 1100 kV line.