XAVIER, C. S. S.; XAVIER, Cinthia Souza dos Santos.
Abstract:
The oil-immersed transformers are consolidated technology equipment; little change has been
added to the projects over the last decades. A change of scenery for stronger growth of the
Brazilian Electric Power System needs more powers and to follow this growth during a
transitional period, the National System Operator decided in 2011 to require equipment able
to withstand diary load cycle with long and short overloading of 20% and 40%. This
requirement has direct consequences in the design of equipment, and also in the design of
other equipment from these transformers connections in substations, like switch disconnectors
, circuit breakers, current transformers and buses in older installations. Chesf transformers
technical specification was changed in order to meet these conditions of overload. However,
the study of the thermal behavior of power transformers deserves special attention since the
design of the equipment. This work aims to evaluate the thermal design of power transformers
from Chesf system acquired in the last two years, through the analysis of temperature curves
of hot-spot. It is desired that the results will contribute and support the technical requirements
of future technical specifications.
