Universalização da energia elétrica através da tecnologia ... - IEE/USP

ABSTRACT
RAMOS, J. E. Universalization of electric energy services through the energized shield
wire line technology (SWL). 348p. Doctorate Thesis. Graduate Program on Energy,
Universidade de São Paulo, 2010.
As one of the major public policies of social inclusion, the universalization of electric energy
services has as a challenge to choose appropriate technological solutions that combine
technical and economic aspects. The energized shield wire line technology (SWL), subject of
this thesis, is in this context. This study aims at evaluating the viability of the SWL
technology (three-phase scheme) installed on a 230 kV transmission line in the State of
Rondônia. The analysis covers its technical, operational, and economic performance. The
former aspect considers the performance of the grounding system regarding the ground
resistance and step and touch voltages, analysis of voltage drop, voltage unbalance and the
load capacity of the installation. The technical issue is deeply held after the analysis of the
system operational performance in Rondônia based on the classification of outages
considering a period greater than 180 months. The operational indices that result from this
evaluation are compared to those corresponding to other technology alternatives in order to
evaluate the viability of SWL technology. The analysis of the causes of interruptions reveals
that lightning has a significant impact on the SWL performance. Thus, an extensive analysis
is carried out regarding the effects of direct and indirect strokes on the SWL, including field
measurements (soil resistivity and tower footing resistance) and laboratory tests
(determination of the positive and negative critical flashover overvoltages of insulator
strings). Simulations are performed using computer programs of proved validity (ATPDraw,
ERM, and CDEGS) for the analysis of lightning overvoltages resulting from direct and
indirect strokes and for the calculation of ground resistance. The effects of important
parameters on the system lightning performance are investigated and the estimated and
observed frequencies of interruptions are compared. The applied methodological procedure is
described in detail, to allow the method to be used in other cases similar to the situations
examined on this study. After a comparative analysis of the performance of the SWL with
respect to other conventional alternatives, reference indices for the operational performance of