Calculation of power losses in the transformer substation

In the article the analysis of power losses in electric networks, which are one of the most important indicators of economic efficiency of their work is given. As the automated measurement tools allowing to supervise current loads of electricity networks elements, are installed in a limited number in power systems, then the calculation of the electricity loss for a period of time based on the calculation of losses for a limited period of time is updated. The article presents the evaluation of the practical formulas effectiveness for determining the number of the greatest losses hours in the calculation of losses on real transformer substation load graphics with a nominal capacity of 1000 KVA transformer, received in the energy audit for a day.