FLORENTINO, M. T. B.; BARROS FLORENTINO, MARCUS TULIOS.; FLORENTINO, M.T.B.; http://lattes.cnpq.br/7745353831423629; FLORENTINO, Marcus Tulius Barros.
Resumo:
This work presents a method for evaluating the operational conditions of polymeric
insulators, focusing on the characterization of corona discharges using attributes extracted
from ultraviolet (UV) images. For this purpose, measurement campaigns and UV images
capturing were carried out in laboratory, in various arrangements, using the Daycor II UV
detection camera, and, simultaneously, the partial discharges signals were measured and
captured using the IEC 60270 classical method. In order to comply with inspection
methodological criteria, the UV camera’s capture parameters were established based on
approximations. In addition, the sensitivity of the main attributes of UV images to the
linear variation of the camera's capture parameters was evaluated in order to compare
which attributes are more or less sensitive to capture conditions. During the digital UV
image processing, the following attributes were evaluated as reference: the area of the
faculae integrated in the capture interval, the mean pixels/frame distribution of the image,
the persistence of the faculae, the number of objects/frame and the persistence map. In
addition to these attributes, the photon counting rate presented by the camera was also
evaluated. The image attributes were correlated with the statistical attributes of corona
discharge pulses and these correlations were addressed in order to characterize the
behavior of polymeric insulators under various conditions of pollution, humidity and
defects. It was possible to obtain safe correlations between the attributes of corona
discharge, both of the image and pulses, and the operational conditions of the insulators,
so that the quantification of corona discharges can be performed using the
parameterization of UV images.