Uma Discussão sobre Indicadores do Estado de Degradação de Cabos Isolados para a Melhoria da Qualidade do Diagnóstico

Abstract

This paper presents a compilation of the dielectric failure mechanisms of medium and high voltage cables. As well as, the various diagnostic methods found in the literature and used in the field, highlighting their advantages and limitations. The methods that use partial discharges to evaluate the insulation condition are emphasized and the main analysis parameter chosen is the magnitude of the apparent charge. In this context, the effectiveness and limitations of the aforementioned methods are discussed, as well as other characteristics extracted from the measurements of partial discharges to complement and, consequently, improve the quality of the results of existing diagnostic techniques. Regarding these complementary attributes, their behavior over time is presented. It is also suggested to include these values in order to obtain more substantiated and effective methodologies for the evaluation of insulation degradation. The use of more effective techniques for monitoring the condition of the cable carries some direct benefits. Which include the better planning of predictive and preventive maintenance, thus raising the level of system reliability. This improvement favors the proposition of management policies for this important asset, widely present both in industries and in power utility companies.