HVDC systems are becoming more common worldwide, specially in Brazil, since the adoption\nof such system for Itaipuâ??s hydroelectric complex in the 1980â??s. Today, the country has the Xingu-Estreito\nbipole, with length of 2375 km. This system crosses a region with high lightning incidence,\na phenomenon which causes faults in power systems. The most widely used model for the positioning\nof the arrestor cables over a transmission line is the electrogeometric model. This model, however,\ndoes not take into account the different potentials over the structureâ??s surface, and therefore presents\nsignificant inaccuracies when assessing the risk of lightning strikes on structures such as a HVDC line.\nThis work then used the Electric Field Deflection (EFD) model with the aid finite elements. Four levels\nof lightning are assessed (I, II, III and IV), with current peaks of 3.9, 5.4, 10.1 and 15.7 kA. It was\nverified that the positive pole tends to attract most of the lightning with shielding failures width\n(SFW) of 12, 8, 4 and 0 m. It was then proposed to move the arrestor cables horizontally. The study\nindicates that this horizontal shifting of the cables in 5 and 8 m toward the side with larger chance of\ndirect incidence reduces the shielding failure widths in 50% for peak current of 3.9 kA and almost\neliminates the strikes for lightning with peak currents of 5.4, 10.1 and 15.7 kA.
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