Donetsk National Technical University

donntu.edu.ua/
Donets'k, Ukraine

Donetsk National Technical University is the biggest and oldest higher education establishment in Donbass, founded in 1921. It was originally located in Donetsk, Ukraine, but as a result of war in Donbass it was relocated to Krasnoarmiysk. In its early years, it was attended by Nikita Khrushchev. Wikipedia.

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Petrovich N.A.,Donetsk National Technical University
Journal of Telecommunication, Electronic and Computer Engineering | Year: 2017

A method is proposed for reducing the computation time while maintaining the stability of the simulation. Examines the joint modelling of objects and devices of relay protection and control. The complexity of the simulation increases when has many sites of a network, especially when real-time algorithms are designed for records in programmable chip devices. Volatility through modelling is associated primarily with the volume of inputs, intermediate and representative accumulated information. Reducing the computation time is necessary due to the exhaustion of a physical resource by clock rate and the effective number of computing processors. The relevance of objectives is maintained in conditions of continuous improvement of the element base of devices, software, technological equipment, and requirements for construction of electric power networks. The method is based on the formation of a semantic signal, which compresses the parametric information on order times. It is shown how the selection of semantic signal in each device will allow known control tasks on the network to be resolved. Shows how to solve problems through simulation of devices taking into account the semantic information flows. For this proposed method of improving the algorithms works on the basis of mutual correspondence of the two equivalent generalized block diagrams of object control and devices for relay protection and control. The obtained quality indicators simulation. Examples of improvement of devices in the task of building high voltage networks for smart-grids with a Petersen's coil are presented. The results are useful for solving problems of the information 'throat', diagnostics 'not under stress', and automatic restoration of the sense of emergency files for mobile, stationary and outsourcing jobs.


Syvokobylenko V.F.,Donetsk National Technical University
Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu | Year: 2017

Purpose. Development of the method for determining the equivalent circuit parameters of induction motor with deep bar rotor using catalog data. Methodology. The methods of analysis, parameter identification, mathematical modeling, solving systems of nonlinear algebraic and differential equations are used. Findings. The methods of taking into consideration the skin effect influence on rotor impedance are analyzed, which allowed adopting the rectangular cross-sectional shape of the rotor bar as a basis. Implication of two different heights for determination of rotor resistance and inductive reactance instead of one height is grounded. The analytical dependences for normalized heights are precised, where, in contrast to known approaches, these heights are determined as proportional to the slip in some unknown k degree, but not as proportional to square root of the slip. Method for selecting the variables of equivalent circuit and method for forming system of nonlinear equations for the numerical determining of variables values by the iterative method are proposed and investigated. The rotor resistance at rated slip, equivalent heights of the rectangular rotor bars, mutual inductance between stator and rotor, resistance of iron losses circuit and exponent for slip in the formula for determining the normalized height are accepted as variables. Using this method, the parameters of equivalent circuit for the deep bar induction motors of different types are calculated and their static characteristics are obtained. Calculated according to the equivalent circuit, the stator currents and moments coincided with the catalog data. The method of using the defined parameters of equivalent circuit for modeling start mode, short circuit and selfstart based on differential equations are presented. Originality. For the first time during synthesis of the equivalent circuit parameters of the induction motor with deep bar rotor, the influence of the skin effect on the rotor impedance is suggested to be determined using not one, but two different heights of equivalent rectangular cross-section of the rotor bar, one for determining the resistance and the other for the inductive reactance. Practical value. The proposed method for determining the equivalent circuit parameters of the induction motor with deep bar rotor the method for calculating of its static and dynamic characteristics is implemented as a program. © Syvokobylenko V. F., 2017.


Zakharov I.I.,Donetsk National Technical University
Journal of Engineering Physics and Thermophysics | Year: 2017

The Sieverts relation is generalized to the case of setting a boundary condition for the equation of convective diffusion of hydrogen in a liquid metal by supplementing it with the electric field strength and the degree of ionization of hydrogen atoms in a melt. The relation obtained agrees qualitatively with the results of laboratory investigations. It can be used in computer simulation of convective diffusion of hydrogen in a liquid metal subjected to the action of external electrostatic field. © 2017 Springer Science+Business Media, LLC


Galiakhmetov A.M.,Donetsk National Technical University
Classical and Quantum Gravity | Year: 2010

Exact general solutions to the Einstein-Cartan equations are obtained for spatially flat isotropic and homogeneous cosmologies with a nonminimally coupled scalar field. It is shown that both singular and nonsingular models are possible. Exact general solutions of an analogous problem in the torsion-less case are derived. The role of torsion in the evolution of models is elucidated. © 2010 IOP Publishing Ltd.


Petrovich N.A.,Donetsk National Technical University
2016 2nd International Conference on Intelligent Energy and Power Systems, IEPS 2016 - Conference Proceedings | Year: 2016

Modelling is an integral part of end-to-end computer-aided design. However, modelling real-time systems remains fragile and long-term. A method is proposed for the sustainable co-simulation of control objects and devices for relay protection and automation at rapid time of a single calculation. The relevance of objectives is the continual improvement of the hardware components, technological equipment and software requirements for the construction of electric power networks. Decisions are based on the representation of objects of information flows. We show how to improve the algorithms of the devices on the basis of mutual correspondence of two generalised block diagrams of the control object and control devices. We highlight the widget for a graphical display terminal, desktop and mobile devices for solving 'bottleneck' problems of information, and outsourcing of auxiliary services networks. An example presents the improvement algorithms of active and passive 'not under stress' self-monitoring. The self-control system will provide automatic maintenance of the efficiency of the network with the Petersen's coil over long-time intervals of operation for multiple collaborating network sites for smart-grids. © 2016 IEEE.


Galiakhmetov A.M.,Donetsk National Technical University
International Journal of Theoretical Physics | Year: 2013

Flat Friedmann universes filled by radiation, stiff fluid and a nonminimally coupled ghost scalar field with polynomial potentials of the fourth degree V(Φ) are investigated in the framework of the Einstein-Cartan theory. Exact solutions are obtained and analyzed for an arbitrary coupling constant ξ. It is shown that both singular and bouncing models with the late-time accelerated expansion are possible. A comparative analysis of the cosmological models with and without stiff fluid is carried out. The role of sources in the evolution of models is elucidated. Some conclusions from comparison of the presented results with other approaches in literature for accelerated expansion are made. © 2012 Springer Science+Business Media New York.


Galiakhmetov A.M.,Donetsk National Technical University
General Relativity and Gravitation | Year: 2013

Exact general solutions for spatially flat isotropic and homogeneous cosmologies with a nonminimally coupled ghost scalar field that has polynomial potentials of the fourth degree are obtained in the framework of the Einstein-Cartan theory (ECT) and general relativity (GR). The special values of coupling constant ξ and restrictions on ξ are found for the above solutions. Some effects of torsion and scalar field potential are elucidated. It is shown that solutions can describe the bouncing models with the late-time accelerated expansion. It is demonstrated that some models admit the unified scenario for dark matter and dark energy: (i) both singular models in ECT with a de Sitter-like asymptotic and with the power-law (t4/3) asymptotic at late times, (ii) singular and nonsingular models in GR with a de Sitter-like asymptotic at late times. © 2012 Springer Science+Business Media New York.


Galiakhmetov A.M.,Donetsk National Technical University
Classical and Quantum Gravity | Year: 2011

Exact general solutions to the Einstein-Cartan equations are obtained for spatially flat isotropic and homogeneous cosmologies with a nonminimally coupled scalar field that has polynomial potentials of the fourth degree V(Φ). An analogous problem is investigated in Einstein's theory of general relativity. Some effects of torsion are elucidated. A comparative analysis of the cosmological models with and without V(Φ) is carried out in the context of the Einstein-Cartan theory. The role of the scalar field potential in the dynamics of models is discussed. © 2011 IOP Publishing Ltd.


Onishchenko V.,Donetsk National Technical University
Mechanism and Machine Theory | Year: 2015

In this paper, we present results from theoretical and experimental investigations into the teeth wear of spur gears of heavy duty machines. During operation, boundary friction and scuffing result on their working surfaces. Theoretical investigations were carried out using the tooth wear model, which takes into account the instantaneous contact temperature according to Blok's concept. The model simulates the continuous interaction of the teeth forms as a function of contact parameters and the effect of these parameters on the shape of the teeth profiles. The validity of the theoretical model was confirmed by experimental investigation. © 2014 Elsevier Ltd. All rights reserved.


Galiakhmetov A.M.,Donetsk National Technical University
General Relativity and Gravitation | Year: 2012

Exact general solutions to the Einstein-Cartan equations are obtained for spatially flat isotropic and homogeneous cosmologies with a nonminimally coupled scalar field and perfect fluid. Some effects of torsion are revealed by solving an analogous problem in general relativity. A comparative analysis of the cosmological models with and without perfect fluid is carried out in context of the Einstein-Cartan theory. The role of perfect fluid in the dynamics of models is discussed. © 2012 Springer Science+Business Media, LLC.

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