Inrush current transients analysis in distribution feeders. / Análise das correntes transitórias de inrush em redes de distribuição.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The purpose of this dissertation is to analyze the inrush currents generated upon the energization of distribution system feeders. These said currents are relevant for typical designs in electric power concessionaries, for example upon calculating the ideal settings for protection devices. It was analyzed (or studies) 291 (two hundred and ninety one) oscilography samples extracted from measuring devices oscilographs were analyzed. These devices were placed in the beggining of distribution feeders, and stored information on such currents both in successful reclosing (hot load) events and re-energization after long periods of outage (cold load) events. All feeders analyzed belong to the AES-Eletropaulo. The inrush current values (in magnitude) were analyzed right after (more specifically 16.66 ms and 100 ms) the feeder energization. For this reason, its corresponding values were studied as a probabilistic variables. This analysis was based on the comparison between measured data and traditional model (application of factor coefficients) calculation results, in this way, observed it that the traditional model yields over-dimensioned results which lead to oversizement of the results currents. It has thus suggested revised, more suitable values (or bands of values) which are bound to ensure a more consistent approximation to the real measurements. Upon comparing the final value (in magnitude) results on the analysis of the factor coefficients for inrush currents for hot load and cold load, it is observed that the cold load inrush currents tend to be higher than those for hot load. Furthermore, it was observed the direct relation of proportionality of the factor coefficients to the ratings capacity transformer power installed along the feeder lines.

ASSUNTO(S)

distribution feeders protection eletrodinâmica redes de distribuição de energia elétrica inrush current

ACESSO AO ARTIGO

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