Resumo:
The transformer is a very important equipment inside of the context of an electrical power
system. It makes possible the electric energy supply. The useful life technique of a transformer
depends on its efficiency, its loading and the temperature of the environment where it operates,
while its economic useful life depends on its useful life technique, the amount of supplied
energy, its price of purchase and the applied taxes of interests. The temperature of the hottest
point of the windings is the most important factor of the loss of useful life technique of the
equipment. This way, how much greater is the amount of the temperature of the hottest point of
the windings it will be transferred to the environment in heat form, the capacity of the transformer
will be greater in supporting a determined overload and its rhythm of aging will be minor.
Therefore, the processes used in the waste of the heat in the transformer are very important
factors in the definition of a thermal profile of the transformer. The estimated useful life technique
of a transformer to operate in full load is 20 years, but when it operates under load, its useful life
is superior 20 years, and when it operates overloaded its life is inferior 20 years. Therefore, the
optimization of the operation of the transformer depends on the traced objective. If the objective
is to supply de maximum amount of possible of energy without putting in risk the economic
viability of the investment, the maximum loading to the transformer does not imply in the
reduction of its useful life technique for an inferior value to its time return of the investment, but if
the objective is to get an additional benefit, the technique useful life of the transformer must be
superior in relation to its time of the return of the investment gotten in detriment of the loading.
