Computer based Study about the Load Regime of a 40 MVA 110/6 kV Transformer

The power transformer is probably one of the most complex and most important equipment existing in the power transmission and distribution system. The evaluation of the technical condition, done with the double purpose of extending its life and reducing the risk of defect, is a complex and important activity, depending on the importance of the transformer in the system. Whether it's routine investigations or special investigations that appeal to the latest techniques and methods of measurement, in order to get a correct diagnosis, the measured data must be as accurately determined, correlated and evaluated on the basis of applicable technical regulations, the latest recommendations and information from the literature, and last but not least, the similar experience. This paper will show a case study for the variation of the load efficiency (the yield) as well as some economical aspects, based on real measurements and technical data.