The characteristics of a submersible induction motor are described with sufficient reliability for practice by the theory of multi-motor electric drive. In this case, the classical circuit of a submersible induction motor is a coupled system of several equivalent-T circuits. In turn, this significantly increases its computational complexity and reduces the speed of ACS. It is proposed to construct a mathematical model of the submersible electric motor in the form of polynomials with significantly higher speed using the methods of experiment planning. In the area of applicability, the differences in the estimation of energy performance do not exceed 1.1%, between the proposed models and classical equivalent-T circuits.

Keywords: automated control system, mathematical model, polynomial, mean absolute percentage error, computational complexity, design of experiment, scatter diagram, modal interval, submersible electrical motor, rotor package

The article considers the assessment of the suitability of solar radiation data from ERA5 atmospheric reanalysis for forecasting problems in the northern territories. The experimental site of the Mukhrino station (Khanty-Mansiysk Autonomous Okrug), equipped with an autonomous power supply system, was chosen as the object of analysis. A statistical analysis of the annual array of global horizontal insolation data obtained using the PVGIS platform has been carried out. Seasonal and diurnal features of changes in insolation are considered, distribution profiles are constructed, and emissions are estimated using the interquartile range method. It is established that the data are characterized by high variability and the presence of a large number of zero values due to polar nights and weather conditions. The identified features must be taken into account when building short-term forecasting models. The conclusion is made about the acceptable quality of ERA5 data for use in forecasting energy generation and consumption in heating systems.

Keywords: ERA5, solar radiation, horizontal insolation, the Far North, statistical analysis, forecasting, emissions analysis, renewable energy sources, energy supply to remote areas, time series, intelligent generation management

The paper examines the causes of the decline in the quality of electrical energy in small settlements. A linear multiplicative model for forecasting electrical loads has been developed based on a time series of electricity consumption in one of the small settlements. A posteriori verification of the multiplicative model has been performed, and the efficiency of the developed model for medium-term forecasting tasks has been demonstrated.

Keywords: electricity consumption, small settlement, linear regression model, multiplicative model, forecasting electrical loads, quality of electrical energy

The article discusses a methodology for predicting global horizontal radiation for the day ahead, based on the concept of characteristic days – typical daily profiles of global horizontal insolation. The method is aimed at use in the absence of operational meteorological information and is intended as an alternative (backup) method of short-term forecasting in autonomous energy systems. As a test case, data from the Murino station (Khanty-Mansiysk Autonomous Okrug), obtained from the PVGIS service based on ERA5 reanalysis, was used. The average and median characteristic days for each month are constructed and the accuracy of forecasts using the RMSE, MAE, MdAE and R2 metrics is compared. It is shown that median profiles provide more stable results in conditions of increased weather variability. The method can be used for approximate planning of photovoltaic installations in remote and northern regions with limited access to meteorological data.

Keywords: solar radiation, global horizontal insolation, ERA5, statistical forecasting methods, forecasting in energy systems, forecasting horizon, forecasting for the day ahead, methods for constructing characteristic days, average and median profiles

One of the causes of local overheating of submersible electric motor caused by the presence of a significant variation of electromagnetic parameters of rotor packages (RP) in the assembly of submersible electric motor is investigated in this paper. Due to the presence in the assembly of RPs with an active resistance much lower than the average resistance of the assembly, the electrical losses in RPs with resistance higher than the average increase, respectively, their heat generation increases. With the help of statistical analysis methods, the distribution of electromagnetic parameters as a two-dimensional random variable was investigated, the "convolution" of the two-dimensional distribution law was constructed. The analysis of the "convolution" of the two-dimensional law of distribution of electromagnetic parameters of the RP showed that there is a high probability of a significant scatter of parameters of the RP in the assembly.

Keywords: submersible electrical motor, rotor package, statistical analysis, local overheating, interrepair period

Forecasting the consumption of electrical energy and power is an urgent and significant problem. This paper discusses current methods for predicting the consumption of electrical energy, reflected in various scientific papers, their analysis is carried out with the identification of more promising forecasting methods.

Keywords: energy consumption forecasting, statistical forecasting methods, neural network forecasting methods, hybrid forecasting methods

In this paper, based on Russian and foreign experience in mathematical modeling of photovoltaic installations, the authors consider the approaches to the construction of these models. The relevance of the research is confirmed by the wide spread of electric energy sources using solar energy. The scheme of photovoltaic element substitution and the dependences describing the processes occurring in it are given. The authors conclude that despite the large number of various mathematical models of photovoltaic elements, all of them can be grouped into two categories. The first category includes models that consider photovoltaic panels as a separate element, and the second category includes models where the photovoltaic panel is a component of a generating complex. Despite the difference in the analyzed approaches, the authors single out a number of parameters that characterize the operation of a photovoltaic panel and are sufficient to obtain simulation results with the required accuracy.

Keywords: photovoltaic panel, mathematical modeling, substitution scheme, distributed generation, power generation

The article discusses the features of the use and applicability of identification of parameters of the equivalent circuit of an submersible electric motors. The possibilities of technical implementation with a given accuracy are evaluated for definition the parameters of submersible electric motors substitution circuits under various external influences, as well as when designing submersible electric motors as an integral part of the electro-technical complex of electrical submersible pump units.

Keywords: submersible electric motor, electrical submersible pump unit, identification of parameters of the equivalent circuit of an asynchronous electric machine, mathematic simulation, crude oil production

The paper considers approaches to optimizing the composition and structure of distributed generation complex for various criteria, such as the cost of electricity and reliability of electricity supply. Based on domestic and world experience, the most promising method of optimization, as applied to the tasks of distributed generation, is carried out. A comparative assessment of traditional optimization methods and methods based on variations of population (evolutionary) algorithms is given.

Keywords: distributed generation, optimization methods, structure of distributed generation plants, cost of electricity, reliability of electricity supply

The article studies the subject of human settlements with decentralized power supply, included into a locally isolated power supply complex. The basic integrated measures were determined for settlements power lines daily load curves. The results are presented, for dependency assessment between the integrated measures for daily load curves and the number of the settlement’s inhabitants. The dependency has been proven to be effectively described by a second order equation. For the dependency, the correlation coefficient, the determination coefficient and the average approximation error have been given.

Keywords: Power line load curve, decentralized power supply zone, locally isolated power supply complex, approximation