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This paper presents a computational tool intended to achieves optimal configurations of conductors with capacity of transmission of energy improved. This arrangement is obtained by calculate and minimize of electric fields at ground level of High Surge Impedance Loading transmission lines. This type of transmission line has higher power transmission rates by utilizing optimized configuration for the conductors. In the present work, an enhanced Deep Cut Ellipsoidal Method is applied to find a new optimized configuration for the phase conductors. The Surge Impedance Loading of the suggested configuration is analyzed. The new proposed configuration results in reduced profiles of electric fields and higher power transmission capacity. [ABSTRACT FROM AUTHOR]

Jordan's formula to calculate the surge impedance of vertical conductors is revised and extended to take into account systems with multiple conductors. Experimental data and the hybrid electromagnetic model are applied in order to validate the derived expressions. Additionally, Jordan's formula is successfully used in the representation of an actual tower as a multiconductor vertical system. The obtained results indicate the usefulness of the derived expressions if an engineering analysis of direct strikes over elevated strike objects is required. [ABSTRACT FROM AUTHOR]

This work presents some results concerning the computational simulation of electromagnetic transients in transmission lines caused by direct strikes of lightning. The research has been carried out by application of a hybrid electromagnetic code developed by the authors' research group. The presented results comprise mostly overvoltage waves developed across insulator strings or at ground wires due to the injection of impulsive current at the top of towers and at the shielding wires along span. The effect of adjacent towers on the developed overvoltage is evaluated. Sensitivity analyses are developed considering a range of values for soil resistivity, variable configurations of tower-fooling and different injected current waveshapes. Some remarkable conclusions concern the grounding effective length for mitigation of overvoltage across the insulator strings, the relevance of midspan strikes and the importance of accurate representation of lightning current waveshape in the evaluation of lightning performance of lines. [ABSTRACT FROM AUTHOR]