This paper presents using of artificial neural network for short-term and medium-term forecasting of electric power consumption by energy provider. As a program for modeling an artificial neural network we chose MATLAB with its Neural Network Toolbox. The article reviews two training algorithms. First was the Levenberg-Marquardt algorithm and the second was Bayesian regularization algorithm. Comparing this algorithms was founded that the second one Bayesian regularization algorithm is more effective for making short-term and medium-term forecasts of electric power consumption. Also it is found, that artificial neural network can be used for one-day forecast management accurate within 2.5% from actual consumption. Comparing the forecasting data with actual data of electric power consumption allowed to the conclusion that artificial neural network which was chosen can be used on practice for forecasting of electric power consumption of energy provider for its effective work on the wholesale electricity market.

Keywords: energy provider, forecasting, plan-by the hour forecast, data base of energy consumption, wholesale electricity market, dynamic series, artificial neural network, Levenberg-Marquardt algorithm, Bayesian regularization algorithm, neural network architectur

The quasi direct currents, which flows through the winding of power transformer, could cause the migration of working point from the knee of the magnetizing curve to the zone of saturation. In that way, the operational mode of power transformer changes. To account the effect of quasi direct current on the operational mode of power transformer was described the model of winding of power transformer with endless magnetic core and cylindrical magnetic cover. Compare the results of accounting model with the model of winding without effect of cylindrical magnetic cover the 20% difference in the characteristics of inductance from magnetizing current in the area of magnetizing currents under 100A was achieved.

Keywords: power transformer, saturation, modeling, the power transformer winding, electric power supply system, quasi direct current, power line, geomagnetic storm, space weather