| n recent years, due to the surge in the demand for electric power, extra-high voltage (EHV) transmission line became widely used for transmitting electric power. While the importance of power transmission increases, the public concern about environmental impact of transmission lines due to associated electric and magnetic fields have increased considerably. Even in situations where opposition is lacking for constructing a new transmission line or upgrading an existing one, the cost of right-of-way may be prohibitive. Consequently, research has been devoted toward more efficient use of existing transmission line right-of-way. Thus, a study of the electric field profile under the transmission line and at the edge of the transmission corridor became an important factor of the overall transmission line design consideration. In this research the charge simulations technique have been implemented to develop a theoretical model for calculating the surface electric field on various parts of a human body standing underneath three-phase transmission line. Moreover, the recently developed efficient charge simulation techniques have been implemented to study the electric field profile underneath the transmission line and on the edge of the transmission corridors, for single circuit and double circuit three-, six- and twelve-phase transmission lines. The following aspects have been investigated: (1) Different line configurations such as equilateral delta, flat and vertical arrangements single circuit of 1, 2, 3, 4 bundled conductors and different double circuit arrangements. (2) The effect of the line height on the electric field profile both under the center of the line and at the edge of the transmission line corridor. (3) The effect of the phase-spacing on the electric field profile both under the center of the line and at the edge of the transmission corridors. (4) The effect of the irregular rolling terrain on the electric field profile under the transmission line and at the edge of the transmission corridors. (5) The effect of the conductor dimensions on the electric field profile both under the center of the line and at the edge of the transmission line corridor. (6) The effect of the shield wires on the electric field profile both under the center of the line and at the edge of the transmission line corridor. (7) The effect of the line sag on the electric field profile both under the center of the line and at the edge of the transmission line corridor. (8) The effect of the bundle conductors' spacing on the electric field profile both under the center of the line and at the edge of the transmission line corridor. (9) The electric field profile for six- and twelve-phases under different line design such as: hexagon, asterisk, triple triangle, horizontal and vertical rectangular, and circular configurations both under the center of the line and towards the edge of the transmission line corridor. (10) The electric field profile under different three phase double circuit design conditions such as: (a)... |
