Contribution to the surge arresters´ evaluation methodology of electrical transmission system. / Contribuição à metodologia de avaliação dos pára-raios do sistema de transmissão de energia elétrica

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Power systems are subject to many types of overvoltages that may provoke interruptions or damage in electrical equipments, compromising the continuity of electrical energy supply to consumers and impacting negatively the power quality indices. One of the most important device used to protect the electric equipments are the surge arresters, which may be classified, in Brazilian power system, by its technology: the first, more antiquated, using gapped silicon-carbide (SiC) surge arrester, and secondly and newer, zinc-oxide (ZnO) surge arrester. The devices of the first type are installed for many years, even above their lifetime, presenting, in such cases, failures in site while operating. The gapped silicon-carbide surge arresters have been substituted gradually by zinc-oxide surge arresters, because it would be economically impracticable to replace them immediately. Therefore, the development of methodologies to evaluate their degradations condition is necessary, in order to avoid the failure of these equipments in site. Measurements of leakage current with third order harmonic analysis showed that important information regarding gapped silicon carbide surge arresters may be obtained, providing subsidies to elaborate a program of maintenance that prioritize the replacement of the most degraded ones.

ASSUNTO(S)

degradation pára-raios gapped silicon carbide surge arrester corrente de fuga terceira harmônica. third harmonic carboneto de silício degradação diagnóstico diagnostics leakage current

ACESSO AO ARTIGO

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