The paper provides a brief overview of publications on the application of mathematical modeling methods in the study of the patterns of functioning of hydroelectric power plants (HPPs). In particular, the following are considered: mathematical models of the total minimum water consumption for a cascade hydropower system in China; a mathematical model of hydropower plants; a mathematical model of two small hydroelectric power plants operating in tandem; accurate modeling of hydraulic transient characteristics in a complex drainage system. The task of filling in the gaps in the data concerning the operation of hydroelectric power plants is formulated. The approach to its solution is proposed to be based on the use of the method described in previous publications by one of the authors and based on the use of regression analysis apparatus. The specific task of filling in data gaps for a hydroelectric unit of one of the Siberian hydroelectric power plants has been solved. The following factors are used: active and reactive power of the electric generator, voltage, current and temperature of the stator iron, rotor current, air cooler hot air temperature.

Keywords: hydroelectric power plant, electric generator, data gaps, predictive analytics, regression model, adequacy criteria

The paper considers a mathematical model of a Darye wind turbine with three blades. The operating mode of the fast rotation of the wind turbine has been obtained. It is called autorotation mode. An assessment of the speed of the wind turbine in this mode was obtained, an assessment of the power and geometric dimensions of the structure under consideration was carried out. Programs have been written in the matlab system and numerical calculation results have been obtained. The efficiency of Darye wind turbines with a different number of blades is compared and it is shown that in practice it is best to use three blades.

Keywords: body, planning mode, stability, geometric dimensions

Computer-based training is one of the most effective tools to reduce accidents in electric power industry. This paper presents the history of development of dispatch personnel simulator technology, from aviation simulators of the mid-20th century to traditional simulators, which finally formed in the late 1990s and the currently developing concept of intelligent simulators. The basic milestones and stages are considered. The authors present the actual problems of the simulator construction, which are the drivers of further development of this technology.

Keywords: dispatch training simulator, DTS, power system personnel training, power system simulation, computer simulation, element management system, EMS

In this paper, a mathematical model of a wind generator similar to the Darya rotor has been developed. The fast turbine rotation mode or autorotation mode is considered. Using the averaging method, the value of the steady-state angular velocity of the wind turbine in the autorotation mode is obtained. A set of programs has been written in the matlab computer system and numerical counting results have been obtained. They are compared with analytical estimates. A parametric analysis of the geometric dimensions of the wind turbine was carried out to obtain a given power. The advantages and disadvantages of this design in comparison with other types of wind turbines are shown. As a result of these calculations, it can be concluded that Darye wind turbines will be effective only for obtaining small power and at small sizes. Large devices fail too often and their maintenance is too expensive.Large devices require too expensive maintenance.

Keywords: wind turbine, autorotation mode, stability, geometric dimensions

The article discusses the selection and evaluation of energy-saving technologies for metallurgical production. Alternative energy sources are ordinary natural phenomena, inexhaustible resources that are produced naturally. Such energy is also called regenerative or "green". The article assessed the climatic characteristics, landscape, level of development of the territory of the location of the research object, analyzed the possibility of using solar and wind energy, hydropower, waste energy, low-potential energy using secondary energy resources. An engineering system based on the use of regenerative heat exchangers or economizers was proposed, which converts the heat of the exhaust gases from the electric steelmaking production into energy used for heating or hot water supply.

Keywords: metallurgical industry, electric steelmaking, alternative energy, energy saving, engineering systems, low-potential energy, secondary energy resources, heat of exhaust gases, regenerative heat exchangers, economizers