Avaliação de técnicas de monitoramento de isoladores poliméricos.

Abstract

Fails in insulates of electrical apparatus are among the main causes of energy interruptions in power systems to its customers. The line transmission performance is directly related with insulates performance. The polymeric insulates has been used since the 1980's when the first commercial version for line transmission was released. Since then, the usage of polymeric insulates has been increasing due to many advantages over the porcelain insulates or the glass one. Nevertheless its long term performance is not known, raising difficulties for evaluating the lifetime expectancy. Nowadays there is no consolidated technique for monitoring polymeric insulates. Several monitoring techniques were evaluated to detected defective or pending defective insulates. The evaluated techniques are partial discharge, UV radiation, IR radiation emitted by heated bodies. Both defective and non-defective polymeric insulates were analyzed in electrical and thermic tests as well in electrical field simulations. Therefore a great data bank of polymeric insulates behavior was raised. Taking into account the results of the tests of partial discharge, is possible to classify the fails of the insulates in low, high and medium seriousness. Analyzing the electrical field simulations, we concluded the electrical field in defective insulates was higher than in non defective ones. The survey of polymeric insulates with corona detector and IR technique has shown good results to detect defective insulates.