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Ruiz Florez, Hugo A., Gloria P. López, Álvaro Jaramillo-Duque, Jesús M. López-Lezama e Nicolás Muñoz-Galeano. "A Mathematical Modeling Approach for Power Flow and State Estimation Analysis in Electric Power Systems through AMPL". Electronics 11, n.º 21 (1 de novembro de 2022): 3566. http://dx.doi.org/10.3390/electronics11213566.
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This paper presents a mathematical modeling approach by which to solve the power flow and state estimation problems in electric power systems through a mathematical programming language (AMPL). The main purpose of this work is to show the advantages of representing these problems through mathematical optimization models in AMPL, which is a modeling language extensively used in a wide range of research applications. The proposed mathematical optimization models allow for dealing with particular issues in that they are not usually considered in the classical approach for power flow and state estimation, such as solving the power flow problem considering reactive power limits in generation buses, as well as the treatment of errors in state estimation analysis. Furthermore, the linearized mathematical optimization models for both problems at hand are also presented and discussed. Several tests were carried out to validate the proposed optimization models, evidencing the applicability of the proposed approach.
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Vikharev, D. Yu, e N. A. Rodin. "Model of implicit pole electric machine based on mathematical formulation of magnetic field in air gap". Vestnik IGEU, n.º 6 (28 de dezembro de 2021): 27–37. http://dx.doi.org/10.17588/2072-2672.2021.6.027-037.
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When modeling transient processes in electric power systems, the issue of designing reliable models of electrical machines is of great interest. The most difficult task is to design the models of synchronous and asynchronous machines. The purpose of the project is to develop mathematical models of synchronous and asynchronous machines based on a generalized model of an implicit-pole machine that considers the change of rotor speed, geometric shapes, and the type of rotor and stator windings. Methods of mathematical modeling of electromagnetic fields in the air gap based on Maxwell equations and methods of the theory of electrical circuits are applied. A system of nonlinear differential equations is considered as a mathematical model of a generalized implicit-pole machine. The key assumption made is the high magnetic permeability of the stator and rotor cores. Technical data of real electric machines have been used for verification. Mathematical models of an implicit pole synchronous machine and an asynchronous machine with a phase rotor have been developed. These models can be used to analyze transient processes in the aggregate without dividing them into electromagnetic and electromechanical ones. The novelty of the models is the fact of non-sinusoidal distribution of the magnetic field in the air gap, various types of multiphase AC windings and rejecting the principle of constant rotation frequency at the time step of the simulation. The proposed mathematical models can be used to solve design problems, to analyze the modes of electric power systems, the operation of relay protection and automation of electric power facilities, and emergency automation. In the future, the equations that consider the influence of the damper circuits and the peculiarities of the windings will be added to the developed mathematical models. The purpose of further research is to develop models of salient-pole synchronous machines and asynchronous machines with a squirrel-cage rotor.
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Bitimanova, Saltanat Serikbaevna, e Asel Asylbekovna Abdildaeva. "Algorithm for optimal control of electric power systems". Bulletin of Toraighyrov University. Energetics series, n.º 4.2020 (17 de dezembro de 2020): 78–91. http://dx.doi.org/10.48081/wddo6475.
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This paper provides information about the current state of the energy system in Kazakhstan. Also, analyzing the technical condition of the structure of the Kazakhstan electro power station, a mathematical model for complex power systems is developed. Algorithms of control with Adams-Bashforth multistep method are developed. There has been conducted the analysis and assessment of significant factors affecting the forecasted dynamics of electric power consumption, built based on multivariate regression and cointegration models.
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Mehta, U., R. Prasad e K. Kothari. "VARIOUS ANALYTICAL MODELS FOR SUPERCAPACITORS: A MATHEMATICAL STUDY". Resource-Efficient Technologies, n.º 1 (9 de maio de 2020): 1–15. http://dx.doi.org/10.18799/24056537/2020/1/218.
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Supercapacitors (SCs) are used extensively in high-power potential energy applications like renewable energy systems, electric vehicles, power electronics, and many other industrial applications. This is due to SCs containing high-power density and the ability to respond spontaneously with fast charging and discharging demands. Advancements in material and fabrication techniques have induced a scope for research to improve the application of SCs. Many researchers have studied various SC properties and their effects on energy storage and management performance. In this paper, various fractional calculus-based SC models are summarized, with emphasis on analytical studies from derived classical SC models. Study prevails such parameterized resistor–capacitor networks have simplified the representation of electrical behavior of SCs to deal with the complicated internal structure. Fractional calculus has been used to develop SC models with the aim of understanding their complicated structure. Finally, the properties of different SC models utilized by various researchers to understand the behavior of SCs are listed using an equivalent circuit.
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Manusov, Vadim, e Javod Ahyoev. "Technical Diagnostics of Electric Equipment with the Use of Fuzzy Logic Models". Applied Mechanics and Materials 792 (setembro de 2015): 324–29. http://dx.doi.org/10.4028/www.scientific.net/amm.792.324.
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The possible technical diagnostics method of electrical power systems (EPS) has been considered, in particular, the electric equipment of substations and electric networks by means of using mathematical apparatus of indistinct sets and fuzzy logic theory. It is shown that on the basis of indistinct expert estimates it is possible to do a prediction for possible causes of failures if preliminary estimates of the failures signs available are known.
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Iakubovsky, Dmitry, Dmitry Krupenev e Denis Boyarkin. "A minimization model of the power shortage of electric power systems with regard to the restrictions on controlled sections". Analysis and data processing systems, n.º 2 (18 de junho de 2021): 95–120. http://dx.doi.org/10.17212/2782-2001-2021-2-95-120.
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A steady trend towards the development of electric power systems leads to their continuous enlargement and sophistication. As a result, new ways of their control appear. In this regard, the existing models and complexes for adequacy assessment may work inadequately and ineffectively in terms of the obtained results adequacy. To assess the current state of the existing models and complexes, we reviewed and analyzed the domestic and foreign software and computer systems. In particular, we considered mathematical models of minimizing the power shortage. This work is based on the problem of modifying mathematical models of minimizing the power shortage used in adequacy assessment of the electric power systems of one of the complexes under consideration. As a modification of mathematical models, it is proposed to exclude the existing method of using the line capacities and start use correct accounting for the maximum permissible active power flow in controlled sections. The experimental part reflected in the paper concerns the testing of options for models to minimize the power shortage, as well as the proposed modifications on various systems, including those consisting of three and seven reliability zones with a variable number of controlled sections and power lines included in them. The results of the study have shown that the proposed modifications are efficient and can be used in the future. The authors also obtained the most adequate results in terms of the physical laws of electric power system operation due to the model of minimizing the power shortage with quadratic losses which takes into account the limitations of power transmission over controlled sections.
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Bebikhov, Yuriy Vladimirovich, Dar'ya Vital'yevna Kazazaeva, Vasiliy Vasil'yevich Fedotov e Il'ya Anatol'yevich Yakushev. "DESIGN AND DEVELOPMENT OF MATHEMATICAL MODELS OF ELECTRIC POWER SYSTEMS OF INDUSTRIAL ENTERPRISES". Materials. Technologies. Design 4, n.º 2 (2022): 5–13. http://dx.doi.org/10.54708/26587572_2022_4285.
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Popov, Denis I. "Mathematical modeling of electric power processes in integrated test benches with dc machines operating on the principle of mutual load". Yugra State University Bulletin 18, n.º 2 (7 de agosto de 2022): 61–67. http://dx.doi.org/10.18822/byusu20220261-67.
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The subject of the study is electric power processes in integrated test benches with DC machines and induction machines operating on the principle of mutual loading. The purpose of the study is to obtain a mathematical model that allows us to study the operation of DC machines under specified conditions. Methods of mathematical modeling, well-known mathematical models of elements of two-link frequency converters, numerical methods for solving differential equations systems using the Runge-Kutta method of the fourth order of accuracy implemented in the Mathcad computer algebra system are used for the study. Mathematical modeling takes into account the nonlinearity of the magnetization curve of the magnetic circuits of electric machines and the pulsations of constant voltage supplied to their windings caused by the operation of converters. As a result of the study, mathematical models of electric power processes in test benches were obtained, which allow calculating currents in all branches of the considered electrical circuits, electromagnetic moments and the rotation frequency of the common shaft. The developed mathematical models can be applied in the design of integrated stands for testing DC machines and asynchronous machines by the method of mutual loading.
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SHEINA, G. "Analysis of mathematical models of transmission lines." Journal of Electrical and power engineering 23, n.º 2 (23 de dezembro de 2020): 16–19. http://dx.doi.org/10.31474/2074-2630-2020-2-16-19.
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This paper investigates a mathematical model of one elements of the power supply system - power transmission lines. The type of models depends on the initial simplifications, which in turn are determined by the complexity of the physics of processes. The task of improving the accuracy of modeling of emergency processes in the power system is due to the significant complexity of modern power systems and their equipment, high-speed relay protection, automation of emergency management and the introduction of higher-speed switching equipment. One of the reasons for a significant number of serious emergencies in the system is the lack of complete and reliable information for modeling modes in the design and operation of power systems. The development of a mathematical model of a three-phase power line, which provides adequate reflection of both normal and emergency processes, is relevant. The advanced mathematical model of power transmission lines allows to investigate various operational modes of electric networks. The improved mathematical model of the power transmission line reflects all the features of physical processes at state modes and transient process and provides sufficient accuracy of the results. The type of mathematical model of power transmission lines depends on the accepted simplifications, depending on the task of research. The purpose of this work is to analyze the mathematical model of the power transmission line to study the modes of operation of the power supply system, with the possibility of its application to take into account all the design features of overhead and cable power lines. The mathematical model of the power line for the study of the modes of operation of the power supply system is analyzed. It is used to take into account the design features of overhead and cable power lines, skin effect.
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Shornikov, Yury, e Evgeny Popov. "Modeling and simulation of transients in electric power systems using hybrid system theory". ITM Web of Conferences 24 (2019): 02012. http://dx.doi.org/10.1051/itmconf/20192402012.
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Transients in electric power systems are of great interest to power engineers when designing a new or maintaining an existing system. The paper deals with using hybrid system theory for modeling and simulation of an electric power system with controllers. The presented technique is rather convenient and recommended as mathematical models of transients in electric power systems with controllers in general contain both continuous and discrete components. The modeling and simulation were carried out in the modeling and simulation environment ISMA, which is briefly presented in the paper.
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Reymov, K. M., G. M. Turmanova, S. K. Makhmuthonov e B. A. Uzakov. "Mathematical models and algorithms of optimal load management of electrical consumers". E3S Web of Conferences 216 (2020): 01166. http://dx.doi.org/10.1051/e3sconf/202021601166.
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The article investigated the static, dynamic and metrological characteristics of new magnetoelastic force sensors taking into account the distribution of Load profile smoothing based on optimal power management is considered to be one of the main ways to ensure efficient operation of energy systems in the short-term planning. Smoothing load profile with a view to reducing costs can be implemented on the ways in which consumers could be affected by administrative and economic measures. Administrative measures are associated with the forced restriction of consumer loads in certain intervals of the planning period. On the one hand, these measures provide benefits to the power system by smoothing load profile, and on the other hand, they cause damage to consumers. Ultimately, in some cases, the damage may be greater than the benefits as a whole to the power system. Therefore, it is advisable to use them in conditions of shortage of power and electricity in the power system. Optimal planning of short-term regimes of power systems according to received, after alignment, rigid load profile can be carried out by traditional methods. The solution of such a problem can be initially carried out under conditions of non-rigid load profile resulting from the directive use of administrative and economic measures carried out with the help of specially developed models. In this regard, the paper proposes a mathematical model of the problem of optimizing load profile of regulated electrical consumers with optimal planning of short-term power system modes, an algorithm for optimal planning of a short-term power system mode with optimizing load profile of regulated power consumers. And also, algorithms are proposed for accounting for simple and functional constraints in the form of equalities and inequalities when optimizing load profile. The effectiveness of the described algorithm for optimizing the short-term mode of the power system, taking into account the optimal load control of adjustable electric locomotives, has been studied using the example of optimal coverage of the load profile of power system, which contains two consumers with adjustable load profile, and two TPPs. Based on the calculated experimental studies computational qualities, it was determined that the proposed mathematical model of the problem is adequate, the developed algorithms for optimal planning of short-term power system modes with optimization of load profile of regulated electric consumers and taking into account various types of limitations have high computational qualities.
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Florez, Hugo A. R., Diogo Marujo, Gloria P. López, Jesús M. López-Lezama e Nicolás Muñoz-Galeano. "State Estimation in Electric Power Systems Using an Approach Based on a Weighted Least Squares Non-Linear Programming Modeling". Electronics 10, n.º 20 (19 de outubro de 2021): 2560. http://dx.doi.org/10.3390/electronics10202560.
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In this work, the state estimation problem of electric power systems is represented through a mathematical programming approach. Initially, a non-linear mathematical model based on the classical method of weighted least squares is proposed to solve the state estimation problem for comparative purposes. Due to the inherent limitations that this classical model presents when dealing with errors in the set of measurements, a new mathematical model is proposed that can be used within an iterative procedure to reduce the impact of measurement errors on the estimated results. Several tests on a didactic 5-bus power system and IEEE benchmark power test systems showed the effectiveness of the proposed approach which achieved better results than the proposed classical state estimation model. The non-linear programming models proposed in this paper are implemented in the mathematical modeling language AMPL. Additionally, to validate the results of the proposed methodologies, the power system operation points are compared with the results obtained using the Matpower simulation package. The results allowed concluding that the proposed mathematical models can be successfully applied to perform state estimation studies in power systems.
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Yu Mikaelian, E., e M. A. Trubicin. "The electric substations compensating devices’ distribution optimization". Journal of Physics: Conference Series 2131, n.º 4 (1 de dezembro de 2021): 042072. http://dx.doi.org/10.1088/1742-6596/2131/4/042072.
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Abstract The article discusses methods for calculating electrical networks when choosing the consumer compensating devices’ location. The main network and calculation module of a complex network is analyzed. The mathematical support of the reactive power factor compensation (PFC) problem is described in regional power systems, the areas of application of individual models are substantiated, and the results of the practical use of the corresponding calculation results are analyzed.
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Pulatov, Behzod, e Shanazarov Alisher. "Optimization of modes of the electric power systems by genetic algorithms". E3S Web of Conferences 216 (2020): 01099. http://dx.doi.org/10.1051/e3sconf/202021601099.
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In article discusses issues for solving optimization problems based on the use of genetic algorithms. Nowadays, the genetic algorithms for solving various problems. This includes the shortest path search, approximation, data filtering and others. In particular, data is being examined regarding the use of a genetic algorithm to solve problems of optimizing the modes of electric power systems. Imagine an algorithm for developing the development of mathematical models, which includes developing the structure of the chromosome, creating a started population, creating a directing force for the population, etc.
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Prodan, Dan, Anca Bucuresteanu, Adrian Motomancea e Emilia Balan. "Decrease in Power Consumption of Hydraulic Systems of Modern Machine Tools". Applied Mechanics and Materials 811 (novembro de 2015): 45–49. http://dx.doi.org/10.4028/www.scientific.net/amm.811.45.
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This paper shows several issues related to decrease in electric power consumption for hydraulic systems of modern machine tools, especially CNCs. A core element in the structure of such systems is the pneumo-hydraulic accumulator. Here, examples are shown for hydraulic systems destined to locking and unlocking of skids and to opening of tool holders. This paper shows mathematical models, diagrams, simulations and certain experimental executions.
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Na, Liu. "MATHEMATICAL MODELING OF HYBRID VEHICLE’S RECUPERATION BRAKING MODE". Management of Development of Complex Systems, n.º 44 (30 de novembro de 2020): 182–87. http://dx.doi.org/10.32347/2412-9933.2020.44.182-187.
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The paper considers the synthesis of mathematical model of recuperation braking mode for hybrid vehicle as a complex control object. The results of computer simulation as diagrams of transients of different operating parameters of hybrid vehicle power system are obtained on the basis of developed model. The analysis of simulation results confirms the adequacy of the mathematic model of the recuperation braking mode of hybrid vehicle to real processes. The developed model can be used for synthesis of automatic control systems of the electric motors, power converters, power supplies and chargers for hybrid vehicles. Hematical and simulation models of the hybrid vehicle’s recuperation braking mode is carried out. The presented models are based on equations of physics of processes and allow to study the recuperation braking mode of the different types hybrid vehicles under various conditions and parameters values (initial linear vehicle’s speed, electrical power of generator, inclination angle and the quality of the road surface, etc.). The designed mathematical model has a rather high adequacy to the real processes, which take place in the hybrid vehicles in the recuperation braking mode, that is confirmed by the obtained simulation results in the form of graphs of transients of the main variables changes. Further research should be conducted towards the development of the functional structures, control devices as well as software and hardware for automatic control systems of the different types hybrid vehicles on the basis of the obtained mathematical and simulation models.
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Iakubovskii, Dmitrii, e Dmitry Krupenev. "Analysis power shortage minimization methods in the modern processing software for adequacy assessment of electric power systems". E3S Web of Conferences 209 (2020): 06008. http://dx.doi.org/10.1051/e3sconf/202020906008.
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Analysis of domestic and foreign software systems for assessing the resource adequacy showed a variety of models and methods used in them. Many software systems use both linear and nonlinear models, these models are optimized according to various criteria to simulate the operation of the system. As tools for solving, software usually use commercial high-level modelling systems for mathematical optimization. However, in addition to the existing ready-made commercial solutions, the authors consider the effectiveness of optimization methods, as well as their parallelized versions, which can be independently implemented and applied as a solver for a specific problem. As a result, it was confirmed that these methods can be used to solve the problem, but they are less effective relative to a commercial solver. From the point of view of accuracy and resources spent on calculations, the most effective of the independently implemented methods turned out to be the parallelized method of differential evolution, which was confirmed by numerical experiments on small systems.
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Shemelova, O. V., E. V. Yakovleva, T. G. Makuseva, I. I. Eremina e O. N. Makusev. "Solving optimization problems when designing power supply circuits". E3S Web of Conferences 124 (2019): 04011. http://dx.doi.org/10.1051/e3sconf/201912404011.
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One of the quickly developing trends in the optimization of electric power grids is system development of operation and optimization of branch circuits which are based on linear programming problems. One of its categories is traffic problem. The paper discusses the formulation of various types of transport optimization problems used in the design of the most efficient power supply systems in the real sector of economy. The construction of arithmetic models of problems is carried out. Their optimality criterion is cost minimization for the design of electrical network diagrams consisting of power lines connecting sources and consumers. Examples of designing optimization power layout in mathematical problems considering the transmission capacity of power lines is given. The paper also touches upon a mathematical problem considering possible transit of capacities. The task is to build a mathematical model and solve problems that ensure minimization of process losses and losses of power when designing electrical networks. The results of solving problems are presented in the form of power supply circuits corresponding to the most optimal linking of source and consumer nodes. The work is of a scientific and practical significance as it considers the problem of optimizing economic costs when designing electric power network schemes. Moreover it is based on a qualitatively different level of use of the traffic problem algorithm. The algorithm for solving the minimization problem obtained in this paper allows developing the necessary computing operations as well as quickly obtaining the results of solving the cost optimization problem in the designed electric power network.
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Maximov, Serguei, Manuel A. Corona-Sánchez, Juan C. Olivares-Galvan, Enrique Melgoza-Vazquez, Rafael Escarela-Perez e Victor M. Jimenez-Mondragon. "Mathematical Calculation of Stray Losses in Transformer Tanks with a Stainless Steel Insert". Mathematics 9, n.º 2 (18 de janeiro de 2021): 184. http://dx.doi.org/10.3390/math9020184.
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At present it is claimed that all electrical energy systems operate with high values of efficiency and reliability. In electric power systems (EPS), electrical power and distribution transformers are responsible for transferring the electrical energy from power stations up to the load centers. Consequently, it is mandatory to design transformers that possess the highest efficiency and reliability possible. Considerable power losses and hotspots may exist in the bushing region of a transformer, where conductors pass through the tank. Most transformer tanks are made of low-carbon steel, for economical reasons, causing the induction of high eddy currents in the bushing regions. Using a non-magnetic insert in the transformer tank can reduce the eddy currents in the region and as a consequence avoid overheating. In this work, analytical formulations were developed to calculate the magnetic field distribution and the stray losses in the transformer region where bushings are mounted, considering a stainless steel insert (SSI) in the transformer tank. Previously, this problem had only been tackled with numerical models. Several cases were analyzed considering different non-magnetic insert sizes. Additionally, a numerical study using a two dimensional (2D) finite element (FE) axisymmetric model was carried out in order to validate the analytical results. The solved cases show a great concordance between models, obtaining relative errors between the solutions of less than two percent.
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Rezaeva, M. A., e R. Y. Semendyaev. "Development and Application of Convolutional Neural Network for the Recognition of Objects in the Scheme of Electric Grid". Journal of Physics: Conference Series 2096, n.º 1 (1 de novembro de 2021): 012020. http://dx.doi.org/10.1088/1742-6596/2096/1/012020.
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Abstract One of the current design problems in the electric power industry is the labor intensity of synthesizing mathematical models to calculate the electrical modes of the network. It takes a lot of time to compose a detailed model of a large power system based on circuit diagram data. To simplify, speed up, and automate the data input, a convolutional neural network is proposed. In this paper the definition of convolutional neural network is given, its elements are described, the architecture of neural network is developed, the accuracy of its work on the schematic diagrams of various power systems is 0.84.
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Vivas, Eliana, Héctor Allende-Cid e Rodrigo Salas. "A Systematic Review of Statistical and Machine Learning Methods for Electrical Power Forecasting with Reported MAPE Score". Entropy 22, n.º 12 (15 de dezembro de 2020): 1412. http://dx.doi.org/10.3390/e22121412.
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Electric power forecasting plays a substantial role in the administration and balance of current power systems. For this reason, accurate predictions of service demands are needed to develop better programming for the generation and distribution of power and to reduce the risk of vulnerabilities in the integration of an electric power system. For the purposes of the current study, a systematic literature review was applied to identify the type of model that has the highest propensity to show precision in the context of electric power forecasting. The state-of-the-art model in accurate electric power forecasting was determined from the results reported in 257 accuracy tests from five geographic regions. Two classes of forecasting models were compared: classical statistical or mathematical (MSC) and machine learning (ML) models. Furthermore, the use of hybrid models that have made significant contributions to electric power forecasting is identified, and a case of study is applied to demonstrate its good performance when compared with traditional models. Among our main findings, we conclude that forecasting errors are minimized by reducing the time horizon, that ML models that consider various sources of exogenous variability tend to have better forecast accuracy, and finally, that the accuracy of the forecasting models has significantly increased over the last five years.
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Bulatov, Yuri, Andrey Kryukov e Aleksandr Cherepanov. "Mathematical models for determining limit operating modes in electrical networks with distributed generation plants". Science Bulletin of the Novosibirsk State Technical University, n.º 4 (18 de dezembro de 2020): 17–36. http://dx.doi.org/10.17212/1814-1196-2020-4-17-36.
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Decentralization of electricity generation based on distributed generation plants is an important segment of the new technology platform for the power industry. On the basis of this approach, significant positive effects can be obtained, which consist in reducing financial costs of energy supply, increasing the uninterrupted power supply, improving the quality of electricity and stimulating the use of renewable energy sources. Effective use of distributed generation in electric power systems requires the development of methods and tools that provide coordinated management of normal, emergency and post-emergency modes. Of particular relevance is the problem of determining the limit operating modes of networks, at the nodal points of which relatively low power generators are connected. In some situations, for example, when using small hydraulic stations, groups of such generators can be located at significant distances for 6-10-20 kV distribution networks from consumption centers. In this case there will be a noticeable limitation of the regions of static aperiodic stability. The article presents the results of developments aimed at implementing methods for determining the limit operating modes by static aperiodic stability in networks with distributed generation plants. The proposed approach is based on the limit modes equations which provide the formation of effective algorithms for the operational finding of points belonging to the boundaries of stability regions. The results of the construction of the indicated areas for a 6 kV electric network with distributed generation plants based on low-power hydraulic stations are presented. Additionally, the transient processes in the studied electric power system were simulated in the Matlab system for various space points of the controlled mode parameters.
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Camargo, José Rui, Jamir Machado da Silva, Ederaldo Godoy Junior, Renan Eduardo da Silva, Luiz Eduardo Nicolini do Patrocínio Nunes e Fabio Silva Rezende. "Direct Thermoelectric Microgeneration Using Residual Heat of Photovoltaic System". Advanced Materials Research 608-609 (dezembro de 2012): 97–113. http://dx.doi.org/10.4028/www.scientific.net/amr.608-609.97.
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All photovoltaic panel heats up when exposed to sunlight and this heating reduces the electrical power output of the same. This work presents the use of this unwanted waste heat, converting it into thermal energy directly by means of the Seebeck effect, which is the direct conversion of thermal energy into electrical energy by means of an arrangement of semiconductor materials that when exposed to temperature gradients generate electric current. In this work emphasis was placed on the influence of temperature on generation processes involved. Thus, the theoretical evaluation, it presents the mathematical models of thermoelectric and photovoltaic systems by raising the curves of voltage, current and electric power generated, and analyses the influence of temperature in each model. To obtain the simulation curves it uses MATLAB ® 5.3, taking into account the parameters of thermoelectric modules and real photovoltaic cells. In practical evaluation, a prototype was assembled containing thermoelectric module attached to the bottom of a photovoltaic panel in order to use the heat energy absorbed by the panel. The data were stored and analyzed, where we observed the influence of temperature in both systems, validating the mathematical modeling. It is the applicability of the mathematical model given the results obtained with the prototype system.
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Mills, V. D., e J. R. Wagner. "Behavioural modelling and analysis of hybrid vehicle steering systems". Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 217, n.º 5 (1 de maio de 2003): 349–61. http://dx.doi.org/10.1243/095440703321645061.
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Hybrid vehicles integrate an internal combustion engine, electric motor with accompanying battery pack and generator, and potentially fuel cells to realize greater fuel economy and reduced emission levels. A variety of powertrain operating scenarios exist including engine with belt-driven generator, electric motor using battery pack and/or fuel cell and, finally, engine and electric motor. Automotive subsystems such as hydraulic power steering cannot be consistently powered by a conventional belt-driven hydraulic pump since the engine may be frequently turned off to conserve energy. Thus, a need exists to investigate the dynamic behaviour of various steering systems for hybrid vehicles in terms of platform steering characteristics and power consumption. In this paper, empirical and analytical mathematical models will be presented for power (e.g. hydraulic, electric and steer by wire) rack and pinion steering units. The influence of chassis, tyre-road interface and steering system non-linearities are introduced. Representative numerical results will be presented and discussed to investigate a vehicle's transient response for each steering system configuration.
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Sidorov, Denis, Fang Liu e Yonghui Sun. "Machine Learning for Energy Systems". Energies 13, n.º 18 (10 de setembro de 2020): 4708. http://dx.doi.org/10.3390/en13184708.
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The objective of this editorial is to overview the content of the special issue “Machine Learning for Energy Systems”. This special issue collects innovative contributions addressing the top challenges in energy systems development, including electric power systems, heating and cooling systems, and gas transportation systems. The special attention is paid to the non-standard mathematical methods integrating data-driven black box dynamical models with classic mathematical and mechanical models. The general motivation of this special issue is driven by the considerable interest in the rethinking and improvement of energy systems due to the progress in heterogeneous data acquisition, data fusion, numerical methods, machine learning, and high-performance computing. The editor of this special issue has made an attempt to publish a book containing original contributions addressing theory and various applications of machine learning in energy systems’ operation, monitoring, and design. The response to our call had 27 submissions from 11 countries (Brazil, Canada, China, Denmark, Germany, Russia, Saudi Arabia, South Korea, Taiwan, UK, and USA), of which 12 were accepted and 15 were rejected. This issue contains 11 technical articles, one review, and one editorial. It covers a broad range of topics including reliability of power systems analysis, power quality issues in railway electrification systems, test systems of transformer oil, industrial control problems in metallurgy, power control for wind turbine fatigue balancing, advanced methods for forecasting of PV output power as well as wind speed and power, control of the AC/DC hybrid power systems with renewables and storage systems, electric-gas energy systems’ risk assessment, battery’s degradation status prediction, insulators fault forecasting, and autonomous energy coordination using blockchain-based negotiation model. In addition, review of the blockchain technology for information security of the energy internet is given. We believe that this special issue will be of interest not only to academics and researchers, but also to all the engineers who are seriously concerned about the unsolved problems in contemporary power engineering, multi-energy microgrids modeling.
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Krupenev, Dmitry, Denis Boyarkin e Dmitrii Iakubovskii. "Research of mathematical models for minimizing power shortage with quadratic losses in power lines and with using network coefficients (sensitivity coefficients)". E3S Web of Conferences 216 (2020): 01009. http://dx.doi.org/10.1051/e3sconf/202021601009.
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The article presents an analysis of the models for minimizing the power shortage used in adequacy assessment by the Monte Carlo method. We analysed two models: a model with quadratic losses in power lines and a model using network coefficients (first-order sensitivity coefficients), that are showing the dependence of the change in power flows through power lines on the balance of generation / consumption in the reliability zones. As a result of the analysis, a conclusion is made about the applicability of the investigated models for adequacy assessment in the long-term planning of the development of electric power systems.
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De Pinto, Stefano, e Giacomo Mantriota. "Power Flows in Compound Transmissions for Hybrid Vehicles". Machines 7, n.º 1 (15 de março de 2019): 19. http://dx.doi.org/10.3390/machines7010019.
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Hybrid electric vehicle (HEV) traction systems are the most promising technologies being characterized by high performance, high fuel efficiency, low emissions and long operating range. Significant improvements can be achieved equipping transmissions with variable transmission ratio such as power-split transmission and a compound power-split electric continuously variable transmission (eCVT). These systems have been introduced to improve vehicle global efficiency since they can maximize the efficiency in different operating conditions. Optimal design and control of these systems leads improvements in vehicles performance and mathematical models, which support the preliminary design phase, can play a key role in this field. In this work, the internal power circulations of “four-port-mechanical-power split device are determined through a dynamic analysis.” Finally, the efficiency of the compound transmission is analytically evaluated, assuming that the overall losses are linked to the eCVT variator.
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Motovilov, A. I., e I. I. Solovejev. "Online electric network capacity assesment". Power engineering: research, equipment, technology 22, n.º 3 (8 de setembro de 2020): 51–59. http://dx.doi.org/10.30724/1998-9903-2020-22-3-51-59.
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Reliability of power supply to consumers and the efficient use of energy resources are priority tasks in the process of operational dispatch control of the energy system. Limitations of the throughput capacity of the electric network increases the value of the non-released power reserve, which in case of violation of the normal mode at one electric power facility can lead to a system accident. The aim of the work is to develop an algorithm for assessing the throughput of the electric network. In this study of the steady-state operating modes of the power system, a method is proposed for online modeling of the parameters of the electric power regime and its verification in a real scheme for determining the throughput of the electric grid. To solve the tasks posed in the work, we used: the theory of multivariate experiment, the theory of systems of linear equations, methods of mathematical modeling, software and computer systems Cosmos. The regression function is used to simulate the power flow over a network element. The methods based on the linearized and complete models with the measured values are compared and estimated using the correlation coefficient. The method can be used in the practice of supervisory control and research organizations in solving problems of improving the characteristics of the regimes, planning and operating the power system in real time, as well as the development of electric networks and power systems. The efficiency of the proposed method was verified during the experiment.
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Obukhov, S. G., G. N. Klimova e A. Ibrahim. "Methodology of optimum unit commitment of energy systems with renewable energy sources". Vestnik IGEU, n.º 6 (28 de dezembro de 2020): 25–38. http://dx.doi.org/10.17588/2072-2672.2020.6.025-038.
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One of the promising ways to improve the reliability and efficiency of power supply for customers in the areas remote from central electrical grid is the use of hybrid power systems with renewable energy sources. The primary task of designing such systems is the unit commitment of the generating equipment that provides the optimal technical and economic indexes of the electric power system. The stochastic nature of generation and nonlinearity of the characteristics of power plants cause a high complexity of solving this problem, which, from a mathematical point of view, is formulated as an optimization problem. An accurate and reliable solution of this optimization problem increases the efficiency of design and operation of hybrid electric power systems with renewable energy sources. And it is a vital task of modern power industry. A probabilistic-statistical methods and models for the analysis of experimental data are used to construct climatic time series and graphs of electrical loads. In addition, to study the operating modes of the electric power system the MatLab system is used for the simulation and modeling, and an evolutionary particle swarm algorithm is used to solve the optimization problem. The original model of solar radiation is used as a part of this methodology. This model provides forecasting the key characteristics of solar radiation in any geographical point of Russia including the areas that have no results of routine actinometric observation. Weibull distribution function is used to forecast daily variations of wind speed. It enhances the validity of forecasting of electricity generation of wind-driven power plant at daily time interval. As a result of the research, a method of optimum unit commitment has been developed for the equipment of electric power systems based on renewable energy sources. The use of the particle swarm algorithm as a part of the methodology provides reliable and accurate determination of the extremum of the objective function, which increases the efficiency of design and operation of hybrid electric power systems with renewable energy sources. The method has been tested on practical examples of optimum unit commitment for the equipment of electric power systems of various configurations and has proven its effectiveness. The technique is implemented as a software application, which ensures the convenience of its practical application. The obtained results can be used by companies involved in the design and operation of electric power systems using renewable energy generating units.
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Plakhtyna, O., A. Kutsyk e A. Lozynskyy. "Method of average voltages in integration step: theory and application". Electrical Engineering 102, n.º 4 (22 de junho de 2020): 2413–22. http://dx.doi.org/10.1007/s00202-020-01039-x.
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Abstract A numerical one-step method of average voltage values in integration step, which allows to algebraize the differential equations for electric circuits of electromechanical systems with semiconductor converters, was described in the paper. The method is proposed for the creation of digital power circuit real-time models of electrical systems in hybrid models that combine digital and physical components. Digital models in hybrid systems must continuously function over a long time period in conjunction with physical objects. The indicated method provides stability of mathematical models, and is also effective in the sense of the amount of calculations. The article describes the application of the method of average voltage values in the integration step to create a hybrid model of power generation system for a ship's power plant with diesel generator. The digital component of the hybrid model, in this case, is power conversion system that includes a synchronous generator driven by a diesel engine, while the physical part is real excitation controller of generator with automatic voltage regulator. The research results obtained on the hybrid model and their comparison with the results of the physical experiment at the laboratory plant are presented.
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Vasiliev, Igor, Boris Kiforenko e Yaroslav Tkachenko. "COMPARATIVE ANALYSIS OF THE EFFICIENCY OF CONSTANT POWER THROTTLED ROCKET ENGINES FOR INTERORBITAL FLIGHTS TO GEOSTATIONAR". Journal of Automation and Information sciences 6 (1 de novembro de 2021): 66–77. http://dx.doi.org/10.34229/1028-0979-2021-6-7.
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Carrying out low-thrust transfers of spacecrafts in the near-earth space from intermediate elliptic to the geostationary orbit using electric rocket engines seems to be one of the most important tasks of modern cosmonautics. Electric rocket engines, whose specific impulse of the reactive jet is an order of magnitude more than in chemical RD, are preferable for interorbit flights with a maximum payload in the case when a significant increase in the duration of the maneuver is permissible. Ability to throttling the rocket engine thrust is traditionally considered as one of the ways to reduce both the engine mass and the required fuel assumptions for performing the specified maneuver. Using the concept of an ideal-rocket engine provides the upper estimates of the payload mass of interborbital flights for the given power level. Accounting for the properties of real engines leads to the need of considering the mathematical models with more strict limits on control functions. A study of the efficiency of three modes of thrust control of an electric propulsion rocket engine was carried out when performing practically interesting spacecraft flights from highly elliptical intermediate near-earth orbits to geostationary orbits. A mathematical model of constant power relay rocket engine has been built. The formulation of the variational problem of the Maer type is given about the execution of a given dynamic maneuver for the throttled and unregulated electric rocket engines of constant power. Using the Pontryagin maximum principle, an analysis of the optimal control functions was carried out, for which the final relations were written out, which allowed to write down the system of differential equations of the optimal movement of the spacecraft, equipped with relay electric rocket engine. The obtained numerical and quality results of the study of the effectiveness of various modes of thrust control of an electric propulsion engine to increase the payload of a given orbital maneuver confirmed the correctness of mathematical models of throttled and relay engines and, in general, the efficiency of using solutions of the averaged equations of optimal motion of a spacecraft for numerical solution of the corresponding boundary value problems in an exact formulation.
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Nigim, K. A., M. M. A. Salama e M. Kazerani. "Solving Polynomial Algebraic Equations of the Stand Alone Induction Generator". International Journal of Electrical Engineering & Education 40, n.º 1 (janeiro de 2003): 45–54. http://dx.doi.org/10.7227/ijeee.40.1.5.
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This paper describes the use of MathCAD's solving block which uses ‘Given’ and ‘Find’ built-in functions to solve nth order nonlinear algebraic equations. Introducing complex energy systems to electrical engineering students in their undergraduate studies is essential to complement many energy conversion courses. Various electric energy-capturing schemes use electric equivalent circuit models that incorporate nonlinear elements with complex mathematical formulas requiring numerical computation. Without incorporating programming tools, the taught material could be vague and a burden for both the student and the lecturer, hindering comprehension of the complexity of the system during the limited lecture hours. This paper introduces a ‘ready to use’ computational and mathematical tool that can be used to solve the non-linear equations quickly. The performance of an energy scheme with non-linear, interrelated variables such as the self-excited induction generator (SEIG) under variable excitation and loading conditions is used as an example. SEIG systems have been intensively proposed for energy capturing to supply power to remote areas from renewable energy resources such as wind and hydro prime mover systems.
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Iakubovskii, D. V., D. S. Krupenev e D. A. Boyarkin. "Application the differential evolution for solving the problem of minimizing the power shortage of electric power systems". E3S Web of Conferences 114 (2019): 03002. http://dx.doi.org/10.1051/e3sconf/201911403002.
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Based on the experience of domestic and foreign researchers, it is known that there are various mathematical models, software systems, and optimization methods used to solve the set tasks for assessing the resource adequacy of electric power systems (EPS). However, the continuous development of EPS leads to the complication and integration of systems against the background of which it becomes necessary to take into account an increasing number of its elements and parameters in one task. Thus, for more effective (in terms of speed and accuracy) solutions of modified models, it is required to analyze and search the most appropriate set of optimization methods. In this connection, the purpose of this study is to analyze the applicability and the effectiveness of applying the method of differential evolution and gradient optimization methods for the model of minimizing the power deficit, which should be also compared. The article considers the analysis of the results of the work that optimization methods, studies were conducted on a test isolated EPS, with various tuning parameters. As a result, it was confirmed that these methods could be used to solve the problem. From the point of view of accuracy and resources expended on calculations, the most efficient among the implemented methods was the method of differential evolution, which was confirmed by numerical experiments on the small systems.
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Seheda, M. S., P. F. Gogolyuk e Y. V. Blyznak. "High-frequency periodic processes in two-winding power transformers". Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, n.º 6 (2021): 96–100. http://dx.doi.org/10.33271/nvngu/2021-6/096.
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Purpose. Mathematical modeling of high-frequency periodic processes in winding power transformers to improve the technology of their design and operation. Methodology. The methods of the formation of mathematical models for the research of high-frequency periodic processes in transformers and methods of solving systems of partial differential equations are applied. Findings. The mathematical model for the research of high-frequency periodic processes in two-winding transformers, with adequate considering of electromagnetic connections of windings and structural parameters of transformers, is created. Originality. To form a mathematical model for the research of high-frequency periodic processes, a substitute scheme of a two-windings transformer, taking into account the parameters of the electric and magnetic circuits of windings and electromagnetic connections between them, is proposed. Practical value. The mathematical model, which allows analyzing the voltage distribution in the transformer windings for high-frequency periodic processes in windings, and adjusting their insulating abilities, is created.
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Solodyankin, Sergey, e Andrey Pazderin. "Increase of Transient Stability Level of Gas Turbine Power Plant Using FACTS". E3S Web of Conferences 139 (2019): 01049. http://dx.doi.org/10.1051/e3sconf/201913901049.
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The article is devoted to the development of the mathematical models of modern devices of flexible alternating current transmission systems (FACTS) when calculating the modes and stability of power systems and to the analysis of influence of the specified devices on transient stability of the generators. The considered scheme contains the generators with the gas turbine drive that have electromechanical parameters providing lower level of transient stability compared to units of higher power rating, which in some cases requires implementation of measures for transient stability enhancement. As examples of FACTS the following devices have been considered: compensating device based on voltage- sourced converter (STATCOM), static synchronous series compensator (SSSC) and the unified power flow controller (UPFC). The known examples of mathematical models of FACTS devices vary in complexity. For a preliminary assessment of the effectiveness of the FACTS devices, it is proposed to use simplified models that adequately reflect their impact on transients. The use of models made it possible to establish a positive impact of the devices on transient stability of generating equipment in case of short circuits in the electric network. The important conclusion here is that the use of the UPFC device based on two converters (with a corresponding increase in cost) compared to one converter device (STATCOM or SSSC) slightly increases the level of transient stability and the limit time of short circuit disconnection. The proposed method of simulating the FACTS devices is suitable for numerical calculations of transient processes in electric power systems, in particular, to estimate the impact on the transient stability level of the parallel operation of power plants in case of disturbances.
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Safaryan, V. S. "STUDY OF TRANSIENT AND STATIONARY OPERATION MODES OF SYNCHRONOUS SYSTEM CONSISTING IN TWO MACHINES". ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations 60, n.º 3 (17 de maio de 2017): 228–36. http://dx.doi.org/10.21122/1029-7448-2017-60-3-228-236.
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The solution of the problem of reliable functioning of an electric power system (EPS) in steady-state and transient regimes, prevention of EPS transition into asynchronous regime, maintenance and restoration of stability of post-emergency processes is based on formation and realization of mathematical models of an EPS processes. During the functioning of electric power system in asynchronous regime, besides the main frequencies, the currents and voltages include harmonic components, the frequencies of which are multiple of the difference of main frequencies. At the two-frequency asynchronous regime the electric power system is being made equivalent in a form of a two-machine system, functioning for a generalized load. In the article mathematical models of transient process of a two-machine system in natural form and in d–q coordinate system are presented. The mathematical model of two-machine system is considered in case of two windings of excitement at the rotors. Also, in the article varieties of mathematical models of EPS transient regimes (trivial, simple, complete) are presented. Transient process of a synchronous two-machine system is described by the complete model. The quality of transient processes of a synchronous machine depends on the number of rotor excitation windings. When there are two excitation windings on the rotor (dual system of excitation), the mathematical model of electromagnetic transient processes of a synchronous machine is represented in a complex form, i.e. in coordinate system d, q, the current of rotor being represented by a generalized vector. In asynchronous operation of a synchronous two-machine system with two excitation windings on the rotor the current and voltage systems include only harmonics of two frequencies. The mathematical model of synchronous steady-state process of a two-machine system is also provided, and the steady-state regimes with different structures of initial information are considered.
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Mishchenko, T. M. "Methodology and Models of Combined Modeling of Electromagnetic Pro-cesses in Electric Traction Systems". Science and Transport Progress. Bulletin of Dnipropetrovsk National University of Railway Transport, n.º 2(92) (15 de abril de 2021): 40–49. http://dx.doi.org/10.15802/stp2021/237404.
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Purpose. The main purpose of the work is the development of identification models and a new method of modeling electromagnetic processes in electric traction systems with simultaneous consideration of all its subsystems, as well as several feeder zones of the electrified section. Methodology. To achieve this purpose, the methods of mathematical modelling, the basics of the theory of random processes and the methodology of their probabilistic-statistical processing, the methods for solving integral equations and analysis of electric traction circuits in electric traction systems are used. Findings. The requirements to be met by an adequate, stochastic identification model of electric traction devices are established. The solution of Fredholm’s integral correlation equation of the first kind is performed. The analytical expression of the identification dynamic model of the electric locomotive DE–1 is obtained and its adequacy is checked. The methodology of combined modeling of electromagnetic processes in devices and subsystems of electric traction systems is developed and presented tabularly. Originality. For the first time it is proposed to use the pulse transition function as identification models of traction substation and traction network with electric rolling stock in predictive modeling of electromagnetic and electric power processes in electric traction systems. A new method has been developed, a method of complex modeling of electromagnetic and electric power processes in the system of electric traction with simultaneous consideration of all its subsystems, as well as several inter-substation zones of the electrified section. For the first time, a method of partitioning the correlation functions for solving an integral correlation equation has been proposed, which allows defining a pulse transition function as an identification model of any subsystem of an electric traction system. Practical value. The developed identification models and the method of combined modeling make it possible to predict electromagnetic processes simultaneously in all feeder zones of the electrified section of the electric traction system. The obtained identification model of the electric locomotive DE–1 can be adapted with its subsequent use in modeling processes in the traction circuits of electric locomotives of other types. The method of factorization of correlation functions used in solving the Volterra integral correlation equation of the first kind (convolution type) can be adapted to the solution of other integral equations, which describe the processes in electric traction systems.
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Peng, Huiming, G. Maksim Popov, Feng Li e Zhiyu Lu. "Dynamic Identification of Equivalent Parameters of Mathematical Models of Power Electrical Equipment of Electromechanical Power Systems". Journal of Physics: Conference Series 2166, n.º 1 (1 de janeiro de 2022): 012024. http://dx.doi.org/10.1088/1742-6596/2166/1/012024.
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Abstract The article describes a method for dynamic identification of AC and DC hybrid power network parameters. The inaccuracy of the parameters of the electromechanical transient simulation model of the power system has caused the obvious difference between the simulation results and the actual measurement, which has restricted its online application. Over the years, the dynamic parameter identification technology based on field test and test has made great progress, but it is far from satisfactory and accurate. There is still a long research journey for the requirements of performance. The online identification method based on the actual dynamic parameters of the power system is a way to solve the problem. The article includes the main microprocessor modules for system parametric identification of load (SIP L) and an overhead power transmission line (SIP TL). The article will analyze the active electrical network and passive electrical network
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Shevchenko, S. Yu, D. O. Danylchenko, S. Yu Bilyk, A. E. Potryvai e G. A. Kovtun. "Considering the effect of dustiness of a photovoltaic module surfaces on solar power generation by matlab software". Electrical Engineering and Power Engineering, n.º 4 (30 de dezembro de 2021): 28–35. http://dx.doi.org/10.15588/1607-6761-2021-4-5.
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Purpose. Improving the simulation model of a solar power plant by creating a block model for accounting for dustiness of the surface of photovoltaic modules when calculating the efficiency of electric power generation by a solar power plant.
Methodology. Use of statistical data processing methods and modeling in the structure of Matlab tools.
Findings. A mathematical model was created, which made it possible to take into account the influence of dustiness of the surface of photovoltaic modules on the efficiency of electric power generation by a solar power station. The model was tested on the real object and the accuracy of modeling was proved.
Originality. The scientific novelty is to create mathematical models that describe the effect of dust on the surface of photovoltaic modules on the efficiency of solar station generation based on the Bouguer-Lambert-Behr law, the blocks of precipitation influence on dust were developed, and the rate of dust accumulation was corrected by taking into account the air humidity.
Practical value. The obtained results will help to improve the accuracy of modeling of all types of photovoltaic systems. These models can be used as the formation of commercial proposals with more accurate schedules of electric power generation, which can significantly increase the accuracy of the choice of rated capacity of equipment.
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Chervonchenko, S. S., e V. Ya Frolov. "Research of the operation of an autonomous electrical complex with a combined composition of backup power sources". Power engineering: research, equipment, technology 24, n.º 4 (17 de agosto de 2022): 90–104. http://dx.doi.org/10.30724/1998-9903-2022-24-4-90-104.
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THE PURPOSE. To analyze scientific and technical information and practical experience of the functioning of autonomous electrical complexes with asynchronous electric motors in the composition. To develop a mathematical model of an autonomous electrical complex of a drilling rig with the presence of an active rectifier, an inverter with pulse-width control signals, as well as combined backup power sources – a battery and a diesel generator set. To establish the influence and expediency of using a combined composition of backup power sources on reliable operation and the possibility of overcoming the voltage failure caused by a sharp increase in load in the steady-state operation of an autonomous electrical complex. METHODS. For the successful fulfillment of the tasks set, this study applied the methods of mathematical modeling of power supply systems, methods of simulation modeling, the theories of automatic control, automated electric drive, and electrical circuits. Also, in research used the MATLAB software package with the built-in Simulink graphic modeling environment to create a mathematical computer model and to process the data obtained analytically. RESULTS. The article describes the relevance of the research topic. The study provides criteria for choosing the composition of backup power sources. Mathematical and simulation models of an autonomous ETC have been developed according to the “power source-frequency converter-industrial load” scheme, taking into account the influence of a non-linear load on the specified power quality indicators. The study has developed the structure of an autonomous electrical complex with a combined composition of backup power sources, which allows to overcome the voltage drop in the network caused by a sharp load surge, while ensuring the required indicators of electricity quality. CONCLUSIONS. The use of a rechargeable battery makes it possible to increase the overload threshold of the main diesel generator set regulated by GOST R 53987-2010 from 30% to 60%, as well as to ensure reliable connection of a backup diesel generator set without interrupting technological processes.
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Gianto, Rudy. "Constant Voltage Model of DFIG-Based Variable Speed Wind Turbine for Load Flow Analysis". Energies 14, n.º 24 (18 de dezembro de 2021): 8549. http://dx.doi.org/10.3390/en14248549.
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At present, the penetration of wind-driven electric generators or wind power plants (WPPs) in electric power systems is getting more and more extensive. To evaluate the steady state performances of such power systems, developing a valid WPP model is therefore necessary. This paper proposes a new method in modeling the most popular type of WPP, i.e., DFIG (doubly fed induction generator)-based WPP, to be used in power system steady state load flow analysis. The proposed model is simple and derived based on the formulas that calculate turbine mechanical power and DFIG power. The main contribution of the paper is that, in contrast to the previous models where the DFIG power factor has been assumed to be constant at unity, the constant voltage model proposed in this paper allows the power factor to vary in order to keep the voltage at the desired value. Another important contribution is that the proposed model can be implemented in both sub-synchronous and super-synchronous conditions (it is to be noted that most of the previous models use two different mathematical models to represent the conditions). The case study is also presented in the present work, and the results of the study confirm the validity of the proposed DFIG model.
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LI, SHAO-HUA, e HSIAO-DONG CHIANG. "STRUCTURE-INDUCED BIFURCATION IN LARGE-SCALE ELECTRIC POWER SYSTEMS". International Journal of Bifurcation and Chaos 18, n.º 05 (maio de 2008): 1415–24. http://dx.doi.org/10.1142/s0218127408021075.
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A structure-induced bifurcation of nonsmooth nonlinear systems is studied and illustrated on electric power system models. The consequence of structure-induced bifurcation is an immediate instability induced by generator reactive power limits. It is numerically shown that structure-induced bifurcation can occur at both small power systems and large-scale power systems. Without taking the structure-induced bifurcation into account in defining power system operating limits, the resulting operating limits can be overly optimistic.
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Ho, Kun-Che, Yi-Hua Liu, Song-Pei Ye, Guan-Jhu Chen e Yu-Shan Cheng. "Mathematical Modeling and Performance Evaluation of Switched-Capacitor-Based Battery Equalization Systems". Electronics 10, n.º 21 (27 de outubro de 2021): 2629. http://dx.doi.org/10.3390/electronics10212629.
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The battery storage system (BSS) is one of the key components in many modern power applications, such as in renewable energy systems and electric vehicles. However, charge imbalance among batteries is very common in BSSs, which may impair the power efficiency, reliability, and safety. Hence, various battery equalization methods have been proposed in the literature. Among these techniques, switched-capacitor (SC)-based battery equalizers (BEs) have attracted much attention due to their low cost, small size, and controllability. In this paper, seven types of SC-based BEs are studied, including conventional, double-tiered, modularized, chain structure types I and II, series-parallel, and single SC-based BEs. Mathematical models that describe the charge–discharge behaviors are first derived. Next, a statistical analysis based on MATLAB simulation is carried out to compare the performance of these seven BEs. Finally, a summary of the circuit design complexity, balancing speed, and practical implementation options for these seven topologies is provided.
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Wang, Hong, e Feng Chun Sun. "Dynamic Modeling and Simulation on a Hybrid Power System for Dual-Motor-Drive Electric Tracked Bulldozer". Applied Mechanics and Materials 494-495 (fevereiro de 2014): 229–33. http://dx.doi.org/10.4028/www.scientific.net/amm.494-495.229.
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Hybrid power systems provide high-performances and high-efficiency power for electric bulldozer. This paper firstly constructs the mathematical model of driving motors system based on the design of dual-motor-driving propulsion system for bulldozer. Secondly, by using the setting values from a bulldozer, simulation work is implemented, and parameters of the hybrid power system are matched, and finally, based on MATLAB/Simulink ,dynamic models for the dual-motor-driving hybrid power system is established, and the simulation results are discussed. Simulation results demonstrate the validity of the hybrid power system model and the matching of the parameters of the hybrid power system is reasonable.
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Pulatov, B. "OPTIMIZATION OF MODES OF ELECTR POWER SYSTEMS BY GENETIC ALGOROTHMS". Technical science and innovation 2019, n.º 3 (18 de setembro de 2019): 224–29. http://dx.doi.org/10.51346/tstu-01.19.3.-77-0030.
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In article discusses issues for solving optimization problems based on the use of genetic algorithms. To date, the genetic use algorithm for solving various problems. Which includes the shortest path search, approximation, data filtering and others. In particular, data is being examined regarding the use of a genetic algorithm to solve problems of optimizing the modes of electric power systems. Imagine an algorithm for developing the development of mathematical models, which includes developing the structure of the chromosome, creating a started population, creating a directing force for the population, etc. As well as the presentation, the selected structure should take into account all the features and limitations imposed on the desired solution, as well as the fact that the implementation of crossоver and mutation algorithms directly depends on its choice. To solve optimization problems, a block diagram of the genetic algorithm is given.
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Zhou, Xiaohang, Jian Liu, Mozhi Ding, Huating Zhu, Mingqi Xu e Qinmiao Li. "Combined optimization of electric heater-heat tank aggregation for wind curtailment". Journal of Physics: Conference Series 2351, n.º 1 (1 de outubro de 2022): 012008. http://dx.doi.org/10.1088/1742-6596/2351/1/012008.
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As the penetration of renewable generation such as wind and solar continues to grow in power systems, system operation calls for curtailment of excess amount of renewable generation. In this regard, an integrated energy system (IES) can be utilized to optimize curtailment. This paper proposes the Electric Heater-Heat Tank Aggregation (EHHTA) as an IES, also an energy coupling device that combines electricity power with heat energy, to deal with redundant wind power curtailment. A combined optimization model was developed in this paper, which incorporates mathematical models of the energy resources. The simulation was carried out based on the practical data in the case study, where the coordinated control of EHHTA and thermal generators from the optimization model was proven to be effective in mitigating wind power curtailment.
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Batsala, Ya V., I. V. Hlad, I. I. Yaremak e O. I. Kiianiuk. "Mathematical model for forecasting the process of electric power generation by photoelectric stations". Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, n.º 1 (2021): 111–16. http://dx.doi.org/10.33271/nvngu/2021-1/111.
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Purpose. Improving the efficiency of photovoltaic power plants in power systems by creating a model for forecasting the amount of electricity produced in the form of a harmonic function and determining the prospects for using the selected mathematical software to develop software applications. Methodology. To determine the amount of electricity generated by photovoltaic plants per day and year, statistical methods are applied using the harmonic function which allows taking into account the main meteorological factors of power change of photomodules. A technique is proposed for taking into account the level of generation by photovoltaic stations to track changes in voltage levels in the connection nodes. Findings. Mathematical models for forecasting the electricity generation of photovoltaic stations for different time ranges are built. The influence of weather factors, the length of daylight and the structure of the local generation system on the level of electricity generated by photovoltaic plants is investigated. Necessity is conditioned to use a harmonic function for forecasting the amount of electricity produced, which improves the efficiency of calculations for new and existing power plants. Originality. The factors of the influence of daylight hours and cloudiness on the level of electricity generation by photovoltaic stations are taken into account, as well as meteorological data that make it possible to predict the value of the amount of electricity generated for a certain period of time. The dependences of the amount of generated electricity by photovoltaic stations are obtained in the form of a harmonious function with reference to a coefficient that takes into account the cloud level for predicting generation volumes. Practical value. Created mathematical models of forecasting by means of harmonic function and analysis of voltage change in nodes of local networks allow increasing the efficiency of photovoltaic stations, simplify calculation of change of levels of voltages in a electric network, the forecasted values of the generated electric power on the day ahead system on the basis of duration of the light day, meteorological data and other external factors at commissioning of photovoltaic stations.
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Baran, P., Y. Varetsky, V. Kidyba e Y. Pryshliak. "A mathematical model for the virtual simulator of the power unit electrical part". IOP Conference Series: Materials Science and Engineering 1216, n.º 1 (1 de janeiro de 2022): 012009. http://dx.doi.org/10.1088/1757-899x/1216/1/012009.
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Abstract The mathematical model is developed for a virtual training system (simulator) of the power unit electrical part operators of a thermal (nuclear) power plant. The model is used to simulating the main operating conditions of the power unit electrical part: generator idling, generator synchronization with the power system, excitation shifting from the main unit to the backup one and vice versa, switching in the power unit auxiliary system, and others. Furthermore, it has been implemented modelling some probable emergency conditions within a power plant: incomplete phase switching, damage to standard power unit equipment, synchronous oscillations, asynchronous mode, etc. The model of the power unit electrical part consists of two interacting software units: models of power equipment (turbine, generator with excitation systems, auxiliary system) and models of its control systems, automation, relay protection and signalling. The models are represented by the corresponding algebraic-differential equations that provide real-time mapping power unit processes at the operator’s request. The developed model uses optimal solving algebraic-differential equations to ensure the virtual process behaviour in real-time. In particular, the implicit Euler method is used to solve differential equations, which is stable when simulating processes in significant disturbances, such as accidental disconnection of the unit from the power system, tripping and energizing loads, generator excitation loss, etc.
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Plakhtyna, Omelyan, Andriy Kutsyk e Mykola Semeniuk. "Real-Time Models of Electromechanical Power Systems, Based on the Method of Average Voltages in Integration Step and Their Computer Application". Energies 13, n.º 9 (4 de maio de 2020): 2263. http://dx.doi.org/10.3390/en13092263.
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In this work, the real-time mathematical models of electromechanical power systems with semiconductor converters based on the author’s method of the average voltages in the integration step are described. As well as the theoretical basics of the method, the algebraization algorithm of differential equations on a time quantum is described. This time quantum in the hybrid model is synchronized with the time quanta of signal samples of the physical part of the model. In the hybrid model, only algebraic equations of electromechanical power systems are present. Software and technical applications of the hybrid models of energy-generating blocks for selected thermal and nuclear power plants are described. In the process curve courses obtained and projected in this paper, the author’s hybrid models are illustrated. In the existing models, the nonlinearity of the electric machines and the semiconductor converters are taken into account. The numerical stability of the method of average voltages in integration step—in the sense of the resistance to computer calculation disturbances—is proven.
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Vereshchago, Yevhen, e Vitalii Kostiuchenko. "Modeling of welding arc power supply diagrams in Matlab / Simulink". Electrical Engineering and Power Engineering, n.º 3 (30 de setembro de 2021): 8–20. http://dx.doi.org/10.15588/1607-6761-2021-3-1.
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Purpose. Creation of virtual blocks and simulation laboratory stands for the study and comprehensive research of the dynamic properties of welding power supplies. Methodology. Review of literary sources on the subject, simulation modeling of electromagnetic processes in the MATLAB software environment, comparative analysis of obtained and available data. Findings. The comparative analysis of means of modeling of power sources of a welding arc is executed. One of the main parameters by which the environments were compared is functionality. Among the considered simulators, Simulink of the MATLAB software environment is the most effective one in the considered systems modeling. Using special features, its user can not only simulate, but also analyze the operation of the over time installation. Mathematical and functional models of welding arc power supplies were built using SimPowerSystems elements and blocks from the Simulink library with the involvement of the MATLAB system itself, which significantly expands the possibilities for such systems modeling. Mathematization of certain processes to some extent shows the level of reliability of the results and the degree of their scientific development. The developed models act as a laboratory, which allows you to set and explore any modes and characteristics. Numerical experiments and comparative analysis of numerical and field experiments are given. Experimental verification of the obtained results on specific examples showed the relevance of the problem and the correctness of its solution. Further research is related to the expansion of the range of simulated power sources of the electric arc, a comprehensive study of their dynamic properties and basic characteristics, experimental verification of the developed models, as well as comparative analysis and development of recommendations for model improvement. Originality. The method of circuit modeling of general-purpose electrical and electronic circuits was further developed by extending it to a new class of objects - the power supply system of electrical installations. Practical value. Construction of mathematical and functional models of complex systems with the involvement of MATLAB allows to take into account their main features, significantly expands the possibilities for modeling, study and research of power supplies. Based on the proposed approach, simulation laboratory stands of specific power supplies were developed and built, which allow to set and study any modes and characteristics.