THE PURPOSE. To consider issues related to the study of methods for determining the sources of violations of the quality of electrical energy in power supply systems, in particular consumers which create rapid voltage changes or voltage fluctuations that create rapid changes in the luminous flux in electric lighting installations. Show that electrical receivers with a sharply variable operating mode are sources of fluctuations in the consumed current and voltage in the electrical network of power supply systems, which in turn manifests itself in the form of unacceptable values of one of the indicators of the quality of electricity - flicker, defined as the subjective perception of fluctuations in the luminous flux of lighting devices. To study the possibilities of determining the places of occurrence of significant voltage fluctuations without the use of expensive and complex instruments for measuring flicker values in the electrical network. To develop a simplified method for determining the locations of electricity consumers that negatively affect the operation of electric lighting systems and, ultimately, the vision of personnel. Conduct a check on a computer model of a simplified method for determining the places of occurrence of voltage fluctuations that are inadmissible in their magnitude, which are expressed in the appearance of significant doses of flicker that exceed the standard values.

METHODS. Solving the problem, a computer model was used, created in the Simulink extension package of the Matlab scientific and technical calculation system.

RESULTS. The article describes the relevance of the problem, discusses the quality of electricity in power supply systems. It has been shown using experimental data that in electrical networks there is an excess of the standard values of flicker doses. The possibility of using interharmonic components of the mains voltage to determine the sources of unacceptable doses of flicker is considered. A simplified method for finding flicker sources based on obtaining the values of the derivatives of currents at various points of the electrical network is presented. Computer simulation of an electrical network diagram with electrical receivers, which have both calm and sharply variable nature of work, has been performed. It is shown that the use of the values of the derivatives of the current at various points of the electrical network makes it possible to identify the sources of the occurrence of unacceptable doses of flicker.

CONCLUSION. The occurrence of significant rapid voltage changes in the electrical network negatively affects vision, which is inevitably accompanied by increased personnel fatigue and can lead to industrial injuries. The results obtained by the authors of the article show that it is possible to use it to determine the places of occurrence of large voltage fluctuations, which are manifested in unacceptable doses of flicker of the derivatives of currents. It should be taken into account when conducting surveys of power supply systems in order to use fairly simple hardware to identify sources of disturbance in the quality of electrical energy.

THE PURPOSE. Smart electrical grids involve extensive use of information infrastructure. Such an aggregate cyber-physical system can be subject to cyber attacks. One of the ways to counter cyberattacks is state estimation. State Estimation is used to identify the present power system operating state and eliminating metering errors and corrupted data. In particular, when a real measurement is replaced by a false one by a malefactor or a failure in the functioning of communication channels occurs, it is possible to detect false data and restore them. However, there is a class of cyberattacks, so-called False Data Injection Attack, aimed at distorting the results of the state estimation. The aim of the research was to develop a state estimation algorithm, which is able to work in the presence of cyber-attack with high accuracy.

METHODS. The authors propose a Multi-Model Forecasting-Aided State Estimation method based on multi-model discrete tracking parameter estimation by the Kalman filter. The multimodal state estimator consisted of three single state estimators, which produced single estimates using different forecasting models. In this paper only linear forecasting models were considered, such as autoregression model, vector autoregression model and Holt’s exponen tial smoothing. When we obtained the multi-model estimate as the weighted sum of the single-model estimates. Cyberattack detection was implemented through innovative and residual analysis. The analysis of the proposed algorithm performance was carried out by simulation modeling using the example of a IEEE 30-bus system in Matlab.

RESULTS. The paper describes an false data injection cyber attack and its specific impact on power system state estimation. A Multi - Model Forecasting-Aided State Estimation algorithm has been developed, which allows detecting cyber attacks and recovering corrupted data. Simulation of the algorithm has been carried out and its efficiency has been proved.

CONCLUSION. The results showed the cyber attack detection rate of 100%. The Multi-Model Forecasting-Aided State Estimation is an protective measure against the impact of cyber attacks on power system.

PURPOSE. Conduct a detailed analysis of existing wind turbines. Analyze the role, place and features of the functioning of wind power plants. Provide various options for generators and schemes for converting wind energy into electricity. Provide recommendations for improving the reliability of wind turbines in smart grids.

METHODS. The article was prepared using analytical methods, statistical, theoretical, factorial and technical methods.

RESULTS. A fixed speed asynchronous generator used in a wind power conversion system (WECS) without a power converter interface draws a significant portion of the reactive power from the grid. This configuration features simple, reliable operation. Wind turbine asynchronous generator with dual power supply. can improve overall power conversion efficiency by performing maximum power point tracking (MPPT), and an increase in speed of about 30% can improve dynamic performance and increase resilience to system disturbances that are not available for turbine types 1 and 2. The use of full-scale 100% power converters will significantly increase the productivity of SPEV wind energy conversion systems, but will slightly increase the cost of the power converter, up to 7% - 12% of the total equipment cost. By using a large number of pole pairs for all types of permanent magnet synchronous generator (PMG), the turbine gearbox can be removed. This type of wind energy conversion system is more resilient to grid disruptions compared to type 1, 2 and 3 wind systems. The review shows that types 3 and 4 technologies are used to most efficiently sell and recycle wind turbines in electricity markets.

CONCLUSION. The article analyzes the features of the functioning of wind power plants operating on the grid. Various options for generators and schemes for converting wind energy into electricity are presented. A detailed analysis of existing wind turbines is provided. Recommendations are given for improving the reliability and efficiency of wind power plants in smart grids.

THE PURPOSE. Evaluation of the power transformer fleet 6-10/0,23-0,4 kV on the example of a branch of PJSC «Rosseti Center»-«Orelenergo».

METHODS. In the work, based on the database of the branch of PJSC «Rosseti Center»-«Orelenergo», an analysis was made of the fleet of power transformers with a higher voltage of 6-10 kV in terms of their number, circuits and groups of connection of windings, rated power, terms of service, as well as energy efficiency classes, taking into account the current standards of the technical organization of PJSC «Rosseti».

RESULTS. According to the results of the study, it was revealed that among the transformer fleet of the branch of PJSC «Rosseti Center»-«Orelenergo», the number of which is 6026 units, 4528 (73% of the total number) transformers have a circuit and a group of winding connections Y/Y0. The most numerous are transformers with rated capacities of 63 kVA, 100 kVA, 160 kVA, 250 kVA (respectively 853, 1454, 1252, 802 pieces of equipment). It was also revealed that only 268 transformers out of 6206, i.e. 4.3% of the total amount comply with the standard of PJSC «Rosseti» in terms of modern requirements for the level of energy efficiency class.

CONCLUSION. A variant of the strategy for replacing power transformers in the branch of PJSC «Rosseti Center»-«Orelenergo» is proposed, within the framework of which trasformers with a given design, circuit and winding connection group, rated capacities and energy efficiency classes are replaced. The implementation of the strategy proposed in the work will make it possible to reduce total electricity losses by 2.3%, as well as increase the share of energy-efficient transformers from 4.3% to 20.4% in the branch of PJSC «Rosseti Center»-«Orelenergo».

THE PURPOSE: The article presents the results of the development of a methodology for the design calculation of reliability and changes in the level of reliability of energy systems, taking into account the influence of control actions based on statistical methods of collection, analysis and models of experimental data processing.

METHODS: The system analysis and generalization of experimental data on technological failures of the main equipment of thermal power plants were used in the calculation assessment.

RESULTS: The objective function of controlling the reliability parameters of the thermal power plant power equipment is proposed. The approbation of the presented objective control function was performed, which showed the adequacy of the results obtained to assess the reliability of the main nodes and elements of the TPP power equipment.

CONCLUSION: The results of the conducted studies show that when determining reliability indicators, it is necessary to take into account the actual technical condition of individual elements and resource-determining functional units of thermal power plant power equipment. The results obtained can be used to develop a methodology for evaluating control actions for calculating the output control parameters and a mathematical model for changing the output characteristics of TPP steam turbines in terms of heat and electric energy generation, as well as at the stage of developing design documentation for the creation of structural elements and practical recommendations in order to extend the service life of power equipment generating systems based on digital technologies.

THE PURPOSE. To consider the features of power supply system of oil and gas production complex, variety of layout of electrical complexes of producing wells. To develop a universal methodology for determining optimal voltage value in power supply center, that is, on substation power bus.

METHODS. When calculating voltage in power supply center, which provides a certain amount of voltage on stator of most remote electric motor, method of equalizing potentials in nodes of outgoing line was used when calculating loads of elements of electrical complexes of producing wells. The development of a methodology for calculating optimal voltage of power supply center was carried out using the method of cognition, which was called ascent from simple to complex. The search for optimal voltage value of power supply center must be carried out by numerical methods with involvement of a software product that allows use of search algorithms.

RESULTS. The article proposes a method for calculating optimal voltage of power supply center of outgoing line of an oil and gas producing enterprise. The developed technique can be applied under a wide range of energy optimization criteria and for any configuration of outgoing line circuit, takes into account technological features of the process of mechanized oil production and ensures a reduction in electricity consumption.

CONCLUSION. The calculation method considered in article makes it possible to develop an optimal list of organizational and technical measures for voltage regulation in distribution network in order to reduce power consumption.

THE PURPOSE. This paper considers the problem of relay protection functioning when the current transformer reaches the saturation mode which is provided by transient processes.

METHODS. MATLAB Simulink software environment allows reproducing the method of statespace representation by using structural blocks. The model is verified by comparison the time to saturation, obtained by calculation and according to the graphical data of the model. The separation of variables method extracts and graphically displays the investigated components.

RESULTS. This paper reveals that applying the requirements of IEC 61869-2:2012 standard, which determines the worst combination of series of unfavorable factors for current transformers in transient mode, can influence a serious impact on the correct operation of relay protection based on current, reactance or differential principle of action. Saturation of the current transformer can lead to both negative results: false operation of relay protection devices and their failure.

CONCLUSION. According to the results of the study, it was determined that the presence of a DC component in the primary short-circuit current has the greatest effect on the protection operation. The delays in the restoration of the RMS value of the short-circuit current reached up to 0.3 seconds, which is comparable with the response time of the second protection zones for microprocessor-based relay protection devices. The DC component of the primary current and the presence of residual magnetic induction of the current transformer provides the largest content of the magnetization current, the largest angular error and also the largest content of the second harmonic component in the secondary short-circuit current.

THE PURPOSE. Determine the impact of the meteorological state of the atmosphere on the efficiency of the functioning of solar thermal and power plants. Modeling the molecular absorption of solar radiation by the atmosphere. Modeling the optical characteristics of the gaseous components of the atmosphere, atmospheric aerosol and clouds.

METHODS. A method for numerical modeling of incoming solar radiation fluxes their functioning to determine the efficiency of solar thermal and power plants. The solar fluxes are calculated by stacking layers in a multi-stream approximation, taking into account the multi-tiered cloud cover and the probability of overlapping the sky with clouds. The absorption of radiation by the gaseous phase of the atmosphere is taken into account by the method of equivalent mass in an inhomogeneous atmosphere. The optical characteristics of the dispersed phase of the atmosphere are calculated using the Mie theory.

RESULTS. An electronic database has been created on the optical characteristics of the gaseous components of the atmosphere, the optical characteristics of atmospheric aerosol and clouds. The effect of anthropogenic impact on the flux of solar radiation falling on the underlying surface is taken into account. The developed modeling takes into account the effect of humidity on the optical characteristics of atmospheric aerosol and its multicomponent composition, depending on the location of the power plant.

CONCLUSION. The information necessary for numerical modeling of meteorological effects on the functioning of solar thermal and power plants is generalized. When calculating solar radiation fluxes, direct illumination of the light-receiving surface by solar radiation, scattered radiation by atmospheric aerosol and clouds are taken into account.

THE PURPOSE. Charging infrastructure is one of the factors influencing the transition to electric vehicles, as the electric vehicles in operation are characterized by a small range and a long battery charge period. Today, the development of the charging infrastructure depends only on the networks of stationary charging stations, which also have disadvantages (high cost, lack of mobility, etc.). Therefore, the purpose of this work is to study the design features of mobile electric vehicle charge units (MCSEU) for the development of draft design documentation for the creation of a new MCSEU project. This issue includes the study of the world market of manufacturers of modern mobile chargers, the study of technical and operational features that are today presented to modern energy storage and storage systems.

MATERIALS. The authors of the article processed and analyzed data on the current state of the charging infrastructure in Russia and the world, based on materials from Russian and foreign authors, as well as information on the development strategy of the electric transport industry in Russia and the world, in particular, data from Madison Gas and Electric.

RESULTS. The obtained analytical results are one of the aspects that will be taken into account when developing mobile charging devices for electric vehicles. This mobile charger technology significantly expands the possibilities of using electric vehicles, in particular electric vehicles, and also solves various problems of the fuel and energy complex associated with autonomous power sources and distributed generation systems.

CONCLUSION. The charging infrastructure is one of the factors influencing the transition to electric vehicles, as the electric vehicles in operation are characterized by a small range and a long period of charging the traction battery. However, this process will be long and in the near future networks of charging stations will be created, including mobile charging units for electric vehicles.

THE PURPOSE. An urgent problem in the development of offshore wind energy is the high cost of generating electricity, which is due to large capital investments. The solution to this problem is possible by increasing efficiency while reducing costs as much as possible, which requires optimal design of offshore wind farms.

GOAL. Development of model for the technical and economic indicators of offshore wind farms based on configuration data, taking into account the factors of climatic conditions and the topography of the seabed at the site of the planned wind farm location.

METHODS. Mathematical modeling using Matlab software environment.

RESULTS. The model evaluates the impact of wake and electrical losses in the main components of the electrical system on the operation of an offshore wind farm, and also allows to take into account the influence of the seabed relief on the economic characteristics of wind turbine foundations. The model was tested on the example of calculating two existing offshore wind farms «Horns Rev 1» and «Horn Rev 2» by comparing the calculated indicators of the average annual electricity generation, capacity factor, capital expenditures and normalized cost of electricity with the actual indicators obtained during their operation. The comparison results show slight deviations within 5% of the actual values.

CONCLUSION. The model for assessing the technical and economic indicators of offshore wind farms was developed and tested on the basis of data on the wind farm configuration and layout, as well as factors of climatic conditions and terrain. Evaluation of the computational speed showed a sufficiently high efficiency of the algorithm, which allows the model to be applied to optimize large offshore wind farms.

THE PURPOSE. The necessity of establishing emission standards for highly toxic substances with carcinogenic properties in the context of the implementation of new principles of state regulation of environmental protection activities at energy enterprises is substantiated and confirmed. The analysis of the features of the formation and burnout of carcinogenic polycyclic aromatic hydrocarbons in the flue gases of boilers during the combustion of coals in lowtemperature conditions of the furnace process is carried out. Based on the analysis, the total and partial indicators of the harmfulness of flue gases were calculated in order to assess and predict the overall toxicity of coal combustion products, taking into account the contribution of carcinogenic substances.

METHODS. When calculating the overall toxicity of flue gases, a systematic analysis and generalization of experimental data on the content of carcinogenic and non-carcinogenic polycyclic aromatic hydrocarbons in the combustion products of low-power boilers was applied.

RESULTS. As a result of the performed study, the contribution of carcinogenic and non-carcinogenic polycyclic hydrocarbons to the overall toxicity of boiler flue gases during the combustion of Azeysky, Mugunsky, Cheremkhovsky and Tugnuy coal was determined. It is shown that substances such as benz(a)pyrene, fluoranthene, pyrene and phenanthrene significantly affect the level of the total indicator of the harmfulness of combustion products from 38.8 to 53.6%.

CONCLUSION. The obtained research results can be applied at energy enterprises at the stage of substantiating the introduction of regime-technological and environmental measures in order to develop measures to improve environmental efficiency through technological rationing of carcinogenic emissions.

THE PURPOSE. Assessment of the state of the art in the development of current limiters based on liquid metal self-healing fuses and an increase in the switching life of self-healing fuses with a composite fuse-link.

METHODS. When solving the problem, the method of literature analysis was used, as well as the method for calculating dependencies for different materials of the fuse-link, the implemented method of scientific computer mathematics.

RESULTS. Literary sources contain information about the designs of liquid-metal self-healing fuses and their research, allowing conclusions to be drawn about their viability and the possibility of obtaining a practical yield. A common disadvantage of the of liquid-metal self-healing fuses design is a limited switching resource due to an increase in the diameter of the fuse-link under the action of arc erosion. A significant effect of increasing the switching resource and the stability of the protective characteristic is possessed by the design of a of liquid-metal self-healing fuses with a composite fusible link. However, in such designs, the switching capacity is reduced. It is shown that the main criterion for the operability of the liquid-metal self-healing fuses with a composite fusible link is the value of the ratio between the value of the shunting resistance and the resistance of the electric ARC. The performance of the liquid-metal self-healing fuses with a composite fusible link is ensured at values of this value below critical.

CONCLUSION. The proposed mathematical expression may turn out to be useful in the development of liquid-metal self-healing fuses with a composite fusible link design, for example, when choosing an electrode material, liquid metal, etc. This will significantly increase the switching resource of the liquid-metal self-healing fuses with a composite fusible link. The condition must be taken into account in the parametric synthesis of the current limiter based on the liquid-metal self-healing fuses with a composite fusible link.

THE PURPOSE. The asynchronous electric motor with a squirrel cage rotor is widely used in the electric driven industry and agricultural machinery. One of the possible ways to improve its energy characteristics is to use a combined 12-zone stator winding instead of the standard 6-zone one. However, in a combined winding with a parallel connection of the «star» and «delta» phases, the phases may not be loaded equally. Therefore, the main purpose of the work under analysis is to study the distribution of currents between the phases of the «star» and «delta» in the asynchronous motor with a combined winding.

METHODS. The study was performed on the AIR71V4 engine, rewound onto a combined winding, in which the real ratio of the active resistances of the «delta» and «star» turned out to be 7% less than the theoretical one. The tests were carried out in no-load and short-circuit mode when powered from a three-phase network, as well as in short-circuit mode when one of the line wires is broken.

RESULTS. The work gives the values of the currents flowing through the phases of the combined winding. For the experimental sample, the deviation of the obtained currents from the theoretical values is determined. Equations of currents are obtained when one of the linear wires is broken. Schemes for switching on the main contacts of a thermal relay for a motor with a combined winding are proposed.

CONCLUSION. The results of the study showed that in an asynchronous motor with a combined winding, in which the real ratio of the active resistances of the «delta» and «star» is less than the theoretical one, the current is not proportionally distributed over the phases. The most preferred circuit for switching on a thermal relay is one in which its main contacts are connected to the «delta» phases, and the thermal relay must be three-pole.

PURPOSE. To develop a variant of the algorithm for the automatic input of the reserve, which consists in transferring the load in case of emergency situations, to make a simulation model in the MatLab® environment corresponding to the developed generalized electrical scheme of the system.

METHODS. When solving the problem, the method of digital modeling was used, which consists in the maximum approximation of the system under study to a real object, implemented by means of MatLab.

RESULTS. It is proposed to study the methods of synthesis of digital models of compensation of voltage drops by the example of a study of an automatic reserve transfer system, demonstrating an approach to modeling this system. When developing models in the MatLab environment, the parameters of real technical elements and devices and their digital analogues are taken into account. The issue of creating a digital model of an electric drive system, including a model of an asynchronous motor with a short-circuited rotor, is considered. The result, after final refinement, can be used to design a real system in production conditions.

CONCLUSIONS. The developed model of the automatic transfer switch system is operable, the time indicators are satisfactory for systems that do not make excessive demands on performances and time intervals. For systems that are sensitive to current inrushes during load transfer, some improvements are required, which are reduced to the implementation of a high-speed automatic switch system. The development of this system is currently at the research stage, namely, the compilation of a load transfer logic that takes into account the phase matching of electrical circuits.

THE PURPOSE. Consider the use of propeller electric installations as part of ship electrical complexes with a single electric power system. Highlight the rudder drives as a special type of electric propulsion of ships in northern latitudes. Investigate unified electric power systems with a propeller electric installation for the existence of power exchange oscillations in them. Propose methods and means for eliminating power oscillations in such systems.

METHODS. To carry out the research, a single electric power system with electric rudder propellers of the world's only asymmetric icebreaker Baltika was considered. All the main elements of such system have been analyzed in detail. Experimental studies were carried out aimed at studying the operating modes of a unified electric power system.

RESULTS. Experimental oscillograms of currents of parallel operating diesel-generator sets in different modes have been obtained. The existence of exchange and in-phase power oscillations during the operation of the unified electric power system of the icebreaker "Baltika" is noted. The data on the negative influence of power oscillations on the operation of the electrical complex of the icebreaker are presented.

CONCLUSION. The use of ice-class sea vessels is an extremely important task for the Russian Federation. The installation of blocks that eliminate exchange and in-phase power oscillations will improve the reliability and efficiency of the use of marine vessels with electric rudder propellers when servicing hydrocarbon production on the Arctic shelf.

THE PURPOSE. Investigation of the operating modes of an isolated power supply system with controlled distributed generation plants, energy storage units and a drive load. Determination of the influence of the proposed prognostic controller of a distributed generation plant on the control parameters and quality indicators of the control process under various operating modes of an isolated power supply system.

METHODS. The studies were carried out on a computer model of an isolated power supply system of an industrial enterprise with a turbine generator plant, a wind generator plant and a high-power electric storage unit, for which a fuzzy control system and a prognostic controller were used. The simulation was performed in MATLAB using Simulink and SimPowerSystems packages.

RESULTS. The article describes a computer model of an isolated power supply system, as well as a structural diagram of the proposed autoprognostic speed controller. The simulation results showed that the combined use of an energy storage unit and an auto-prognostic generator rotor speed controller makes it possible to ensure the stability and survivability of an isolated power supply system, increasing its damping properties. The use of a fuzzy control system of a wind-generating plant made it possible to ensure its stable operation in all considered modes.

CONCLUSION. The auto-prognostic speed controller, which does not require special settings, and the energy storage unit provide high quality control indicators in normal and emergency modes. It is advisable to conduct further studies to coordinate the actions of the control system of the electric energy storage unit and the auto-prognostic speed controller of the distributed generation plant.