Determination of critical ambience temperature by power transformers loading

摘要

This paper presents results of the analysis of the rate between permitted maximal peak load of power transformer x/10 kV/kV and its recorded peak load, both as functions of ambience temperature's average daily value, θa. Concerning the fact that these functions depend on consumption types, three different consumption areas were analyzed: with electrical, non-electrical and mixed space heating manner. Functions mentioned above were defined according to relevant annual load charts. It has been determined that both functions' types can be approximated with S-curves or third degree functions. By these functions' comparison, man can determine critical value of ambience temperature, by which the equivalence of thermally permitted peak load of a power transformer and its consumption area's peak load demand, guaranties that this power transformer would not be overloaded, by any other ambience temperature.