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An electric potential appears at floating wires located within a strong electric field. This phenomenon can be used to supply small isolated communities situated close to Extra-High Voltage transmission lines. This non-conventional distributed generation system has been studied for the last years. However, to improve the power generation system the optimal position of the floating wires, number of wires used, bundle radius, and type of wires must be properly identified. This paper presents a mathematical model solved with genetic algorithm to design a collector system with optimized induced voltage and minimized project cost, identifying the optimal reactor used for voltage regulation. The algorithm was applied to design a collector system that can tap-off 100 kW from a 230 kV transmission line. The trade-off between objectives and the Pareto optimal solutions were evidenced via several simulations using the weighting sum approach. These results allowed to identify a final geometry according to a-posteriori designer preferences. [ABSTRACT FROM AUTHOR]

This paper presents a comparison of secondary electric arcs behavior for reclosing applications. The main objective of the paper is to show the differences in secondary arcs during simulations, laboratory tests and real life events. These comparisons can help engineers develop adaptive reclosing algorithms and improve power system stability. A software arc model, a laboratory test result and field events' harmonic contents were analyzed. Although the harmonics may differ in each method, they all provide enough information to be used in the reclosing algorithms. [ABSTRACT FROM PUBLISHER]

This study involves the application of Short Time Discrete Fourier Transform in order to obtain the harmonic content of voltage between the terminals of 647 artificially generated long electrical arcs. Non-confined tests were conducted on three 500 kV towers specially built inside a laboratory facility, in order to represent as close as possible actual transmission line conditions. The 1-s duration arcs were artificially generated along the 4 m insulator string of a 500 kV tower by imposing a sustained 60 Hz current. The arc voltage harmonic content can be used to identify the moment at which the arc is stabilized in the air and only after this instant measured data can be used to derive mathematical arc model. A statistical analysis of the results, considering only the period for which the arc is stabilized, enabled the establishment of the harmonic signature of the electric arcs for a large arc current amplitude range. From the results it can be stated that an accurate arc model should properly reproduce the presented harmonic content for any arc current level. [ABSTRACT FROM AUTHOR]