Resumo:
The Infrared Thermography, when correctly applied, is an excellent predictive maintenance tool for high voltage substations. Its utilization allows the detection of failures in their initial phases avoiding, therefore, undesired not programmed maintenances. Consequently there is an increasing in the inspections safety, time between maintenances and power system reliability, reducing costs. However, there are limitations in its applications, mainly when it is carried out in outdoor environments. In these conditions, the obtained results can be considerably influenced by environmental quantities, turning the analysis more difficult and diagnosis of inspected equipments less reliable.
The aim of this dissertation is at to define the main limitations and influences on a thermographic inspection on uncovered high voltage substations. It analyzes the influence from who executes the inspection (the thermographer), the limitations of equipment employed in the inspection (thermal camera) and the conditions of equipment under inspection. The influences of environmental factors over the measuring and the analysis of thermal anomalies identified are also considered. It presents the implications of these influences, through tests in laboratory and in field, proposing procedures to reduce or to avoid them. After that, the development of an inspection methodology in order to get more reliable results is made, enabling a more consistent analysis of the found failures.
