Economic transformer load estimation considering power quality

On the base of the analysis of the actual distribution transformer load in a real urban electric power system, it will be shown that the conventional approach for the estimation of the economic transformer load, which is based on the criterion of transformer operation cost minimization, is not sufficient for the decision about the permissible load of distribution transformers in the grid. In modern urban networks it is necessary to take into consideration power quality requirements for the economic transformer load estimation.