Uma análise estatística da coordenação de isolamento em seccionadores de alta e extra-alta tensão.

Abstract

This dissertation evaluates the insulation coordination of three disconnectors isolated by air, with respect to switching surges for electrical systems with rated voltages above 300 kV, and atmospheric surges for voltages below 300 kV. From assay disconnectors isolated by air, in extra-high-voltage laboratories, data is collected for checking insulation coordination on the electrical distances of "Open-Gap" and dry arc distance, on the insulator, which varies the breakdown voltage values between contacts and fase-to-ground, respectively. Then the statistical analysis is performed on the normal distribution curve values, based on the method "up and down", on breakdown voltage values of the fifty percent of impulse voltages (U50%) and the dispersion of the measured values – standard deviation ( ). Thereafter, it is taken to analyze the results, obtaining the conditions for which, it may ensure the insulation coordination of the disconnector. Based on this analysis, it is proposed to more detailed laboratory studies and indicates the inclusion of dielectric tests proving the insulation coordination of the disconnector in the type testing of the Brazilian technical standard.