scholarly journals Model of implicit pole electric machine based on mathematical formulation of magnetic field in air gap

Vestnik IGEU ◽  
2021 ◽  
pp. 27-37
Author(s):  
D.Yu. Vikharev ◽  
N.A. Rodin
Keyword(s):  
Magnetic Field ◽  
Power Systems ◽  
Mathematical Models ◽  
Electric Power ◽  
Mathematical Formulation ◽  
Electric Power Systems ◽  
Air Gap ◽  
Transient Processes ◽  
Time Step ◽  
Asynchronous Machines

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.

scholarly journals Modeling and simulation of transients in electric power systems using hybrid system theory

2019 ◽  
Vol 24 ◽  
pp. 02012
Author(s):  
Yury Shornikov ◽  
Evgeny Popov
Keyword(s):  
System Theory ◽  
Power Systems ◽  
Power System ◽  
Mathematical Models ◽  
Modeling And Simulation ◽  
Electric Power ◽  
Hybrid System ◽  
Electric Power Systems ◽  
Electric Power System ◽  
Simulation Environment

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.

scholarly journals A study of the transient processes in the physical model of the electric power systems with predominant part of the renewable energy sources

2021 ◽  
Vol 286 ◽  
pp. 02009
Author(s):  
Ivaylo Nedelchev ◽  
Hristo Zhivomirov ◽  
Yoncho Kamenov
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Power System ◽  
Electric Power ◽  
Physical Model ◽  
Wind Power ◽  
Electric Power Systems ◽  
Electric Power System ◽  
Transient Processes ◽  
Energy Sources

The renewable energy take part in the most of the electric power systems in the modern world. The part of this type of energy in the global electric power system, as well as in the local scale, increases with the setting the stricter requirements for decreasing the level of the carbon dioxide emissions. This is the result of the newest international conventions and decision for saving the nature. By these conditions, the electric power systems are forced to work with more different types of energy sources: wind power, photovoltaic, biomass plants etc. Switching of such miscellaneous power sources, leads to complicated transient processes, which are developed due to specific electrical parameters, especially harmonic components, of the synchronous generators, photovoltaic and wind power plants. This paper represents data from measurements of the transient processes into the physical model of the electric power system with predominant part of renewable energy and assesses the applicability of the model. For conducting this study, the multichannel DAQ measurement system is used.

scholarly journals A minimization model of the power shortage of electric power systems with regard to the restrictions on controlled sections

2021 ◽  
pp. 95-120
Author(s):  
Dmitry Iakubovsky ◽  
◽  
Dmitry Krupenev ◽  
Denis Boyarkin ◽  
◽  
...  
Keyword(s):  
Power Systems ◽  
Mathematical Models ◽  
Electric Power ◽  
Power Flow ◽  
Power Transmission ◽  
Electric Power Systems ◽  
Variable Number ◽  
Electric Power System ◽  
Active Power Flow ◽  
Adequacy Assessment

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.

scholarly journals Essential Material Knowledge and Recent Model Developments for REBCO-Coated Conductors in Electric Power Systems

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1892
Author(s):  
Frederic Trillaud ◽  
Gabriel dos Santos ◽  
Guilherme Gonçalves Sotelo
Keyword(s):  
Magnetic Field ◽  
Power Systems ◽  
Electric Power ◽  
Critical Current ◽  
Current Density ◽  
Applied Magnetic Field ◽  
Superconducting Devices ◽  
Electric Power Systems ◽  
Correct Operation ◽  
Wide Range

The manufacturing of commercial REBCO tapes, REBCO referring to Rare-earth barium copper oxide, has matured enough to lead to a variety of applications ranging from scientific instruments to electric power systems. In particular, its large current density with a high n index and low hysteresis losses make it a strong candidate for specific applications relying on the dependence of its resistance on current. Despite its advantages, there are still issues that remain to be addressed, such as the scarcity of experimental data for the basic characteristics of the superconductor over a wide range of temperature and applied magnetic field, the inhomogeneity of these characteristics along the conductor length, as well as the anisotropy of the critical current and n index with respect to the direction of the applied magnetic field. To better utilize the technology, it is therefore sensible to understand the relevancy of these issues so that one could simulate as accurately as possible the physics of the superconductor, at least the dynamics that may impact the correct operation of the superconducting device. There are different levels of modelling to achieve such a goal that can either focus on the performance of the superconductor itself, or on the whole device. The present work addresses some of the latest developments in the modelling of commercial REBCO tapes in power systems with a particular focus on the thermoelectric behavior of superconducting devices connected to external circuits. Two very different approaches corresponding to two different scales in the modelling of superconducting devices are presented: (1) analysis using equivalent models and lumped parameters to study the thermoelectric response of superconducting devices as a whole, (2) Finite Element Analysis (FEA) to compute distributed fields such as current density, magnetic flux density and local losses in tapes. In this context, this paper reviews both approaches and gives a broad variety of examples to show their practical applications in electric power systems. Firstly, they show the relevance of the technology in power systems engineering. Secondly, they allow inferring the necessary level of model details to optimize the operation of superconducting power devices in power grids. This level of details relies completely on the knowledge of some basic measurable properties of superconducting tapes (critical current and n index) and their cooling conditions.

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