Wyniki wyszukiwania - BazTech

1

The principles of the creation of the control system for the pumping complex variable-frequency electric drive, taking into account the alteration of the current parameters of the hydrosystem

Zagirnyak M., Kovalchuk V., Korenkova T.

Przegląd Elektrotechniczny

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2018

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R. 94, nr 12

38--41

EN

We demonstrated that the alteration of the basic parameters of the pumping and pipeline equipment accompany the pumping complexes functioning in the unsteady operation modes. We considered the special features of the creation of the extreme system of the automatic control of the pumping complex variable-frequency electric drive taking into account the alteration of the current parameters of the electrohydraulic equipment. We presented the algorithm of the operation of the considered extreme system. The algorithm grounds on the identification of the pumping complex parameters based on the equations of the balance of the hydraulic power harmonic components between the power supply and the elements of the hydrosystem.

PL

Wykazano, że zmienność podstawowych parametrów pompowania i wyposażenia rurociągowego wprowadza system pompowania w stan nieustalony. Rozważono specjalne właściwości tworzenia ekstremalnego systemu automatycznego sterowania napędem zespołu pompowego przy zmienności parametru prądowego w urządzeniu elektrohydraulicznym. Zaprezentowany został algorytm działania rozważanego systemu ekstremalnego. Algorytm bazuje na identyfikacji parametrów zespołu pompowego bazujące na równaniu równowagi pomiędzy mocą zasilania i elementów hydrosystemu.

2

The automation of the procedure of the electrohydraulic complex power harmonic analysis

Zagirnyak M., Kovalchuk V., Korenkova T.

Przegląd Elektrotechniczny

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2018

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R. 94, nr 1

1--4

EN

A possibility of application of the method for the harmonic analysis of power signals in the non-stationary modes of electrohydraulic complexes operation is demonstrated. To automate the procedure of power harmonic analysis an energy analyzer is created. It enables the research of the electrohydraulic complex power processes when they change in real time with preservation of all information about the initial power-forming signals. It is obtained that the wave processes in the pipeline in non-stationary modes are accompanied by increase of the power signals variable components, especially, their low-frequency component. It is proposed to use the indices based on determination of the power root-mean-square values to assess the energy conversion processes in the electrohydraulic complex.

PL

W pracy zademonstrowano możliwość aplikacji metody analizy harmonicznych sygnałów mocy w niestacjonarnych modach układów elektrohydraulicznych. Do zautomatyzowania procesu stworzono procedurę harmonicznej analizy mocy w analizatorach energii. Umożliwia to badanie procesów w układach elektrohydraulicznych w czasie realnym, podczas ich zmiany z zachowaniem wszystkich informacji o początkowych sygnałach. Otrzymano, że niestacjonarne procesy falowe w rurociągu stowarzyszone są ze wzrostem składników sygnałów mocy, specjalnie tych o niskiej częstotliwości. Zaproponowano wykorzystanie indeksów bazujących na określeniu wartości skutecznej w celu oszacowania procesów przemiany energetycznej w układzie elektrohydraulicznym.

3

The complex phenomenological model for prediction of inhomogeneous deformations of railway ballast layer after tamping works

Sysyn M., Gerber U., Kovalchuk V., Nabochenko O.

Archives of Transport

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2018

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Vol. 47, iss. 3

91--107

EN

The given article considers the method of calculating the track geometry deformation with respect to uneven accumulation of residual deformations along the track. The technique proposes two significant changes in existing approaches to calculating the efficiency of the ballast layer. The transition from the approach of allowable stresses design in the ballast layer to the deformative approach of accumulations of track geometry deformations allows us to draw conclusions regarding the intervals of track tamping and the duration of ballast layer life cycle. The transition from the determinative to probabilistic approaches makes it possible to draw conclusions not only from the average unevenness, but also with regard to all possible facts of unevenness. The method is based on the mechanism of sudden and gradual deformations occurrence, which depends on a number of key factors: dynamic stresses on the ballast, non-uniformity of track elasticity, performance of current maintenance work. Based on the experimental studies results, the dependencies of sudden deformations and the intensity of gradual deformations on the level of stress on the ballast layer were established. The experimental results of the influence of the subballast base elasticity on the intensity of accumulation of residual deformations are shown. On the basis of the developed method, the prediction of track geometry deterioration for a given structure of the track, the rolling stock and the permissible level of geometric deviations for track maintenance is presented.

4

Estimation of dynamic loads in an electrohydraulic complex at different laws of supply voltage frequency variation

Zagirnyak M., Kovalchuk V., Korenkova T., Berdai A.

Przegląd Elektrotechniczny

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2017

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R. 93, nr 1

237--240

EN

It is shown that direct start of electrohydraulic complex pump units is characterized by essential surges of current, dynamic torque and head. An electrohydraulic complex mathematical model for research of supply voltage frequency variation law influence on transient processes in the system is proposed. It is shown that transient processes behavior in the electrohydraulic complex is influenced by the time of acceleration/braking, pipeline geometry, presence of static head at particular sections of the hydraulic network, the method of the technological mechanism start-up. It is proved that the use of smooth start/stop of the pump unit makes it possible to decrease dynamic loads on the motor, eliminate occurrence of oscillations in the head and flow rate signals, reduce power losses at the start. Basic recommendations as to the choice of the law of input impact generation are formulated.

PL

Wykazano, że bezpośredni start system elektrohydraulicznego charakteryzuje się istotnymi przetężeniami prądowymi oraz dynamicznym momentem. Zaprezentowany został złożony model matematyczny zjawisk elektrohydraulicznych do badania wpływu zasilania napięciowego na procesy przejściowe w systemie. Pokazano, że przebiegi procesów przejściowych w układach elektrohydraulicznych zależą od czasu przyspieszania/hamowania, geometrii rur, obecności statycznej głowicy w poszczególnych sekcjach systemu oraz od metody technologicznej do rozpoczynania procesu, Wykazano, że użycie łagodnego startowania/hamowania pompy czyni możliwym dynamicznego obciążenia silnika, wyeliminować oscylacje głowicy I sygnałów przepływowych, jak również zredukować straty mocy przy starcie, sformułowano podstawowe rekomendacje co do wyboru zasady generacji impulsów wejściowych.

5

Research of derailed wheelset impact marks on the concrete sleepers

Luchko J., Bolzhelarskyi Y., Kovalchuk V., Sysyn M.

Materiały Budowlane

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2016

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nr 11

31--32

EN

The process of destruction of reinforced concrete sleepers under the railway wheel impact loading is being studied. The article proposes the impact test method of sleepers using a pendulum impact machine. It was developed a device to measure the parameters of impact marks. Using the proposed device it was analyzed the form of the impact marks left by the railway wheel.

PL

W artykule przeanalizowano charakter uszkodzenia żelbetowych podkładów kolejowych poddanych działaniu dynamicznego obciążenia udarowego od kół taboru kolejowego (na bazie badań z użyciem kafara wahadłowego). Przeprowadzono badania laboratoryjne żelbetowych podkładów kolejowych aż do zniszczenia. Opracowano urządzenie do pomiaru geometrycznych parametrów śladu uderzeń koła pociągu.

6

Identification of electrohydraulic complex parameters using instantaneous power components

Zagirnyak M., Kovalchuk V., Korenkova T.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 12

286-289

EN

It is proved that identification of electrohydraulic complex parameters is to be based on equations of power balance of all the components of power channel instantaneous power. An electrohydraulic complex equivalent circuit with division of parameters into active resistance and inductive reactance is proposed, which makes it possible to take into consideration inertial loss of head in the pipeline. A sufficient number of identification equations for determination of the hydrosystem necessary parameters are obtained. It is pointed out that the offered energy method can be used to solve problems of identification of parameters of electrohydraulic complexes with group operation of pump units with controlled and uncontrolled pump electric drive.

PL

Przedstawiono metodę identyfikacji parametrów złożonego układu elektrohydraulicznego bazującą na równaniach bilansu mocy. System hydrauliczny jest reprezentowany przez rezystancję i indukcyjność. Zaproponowana metoda może służyć do analizy systemu złożonego z pomp sterowanych elektrycznie.

7

Dynamical systems with internal degrees of freedom in non-Euclidean speces

Sławianowski J. J., Kovalchuk V., Gołubowska B., Martens A., Rożko E. E.

Prace Instytutu Podstawowych Problemów Techniki PAN

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2006

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nr 8

1-121

EN

The primary concept of Newton mechanics is that of the material point moving in three-dimensional Euclidean space. A good deal of the theory depends only on the affine sector of geometry. The metric structure becomes essential when constructing particular functional models of forces; the concepts of energy, work, and power (time rate of work) also depend in an essential way on the metric tensor. The Galilei relativity principle implies that,l as a matter of vactl, it is not three-dimencional Euclidean space but rather four-dimensional Galilean space-time that is a proper arena of mechanics. This space-time has relatively complicated structure, does not carry any natural four-dimensional metric tensor and fails to be the Cartesian product of space and time. There exists the absolute time, but the absolute space does not. In the sequel we concentrate onf the other kind of problems, so the analysis of the subtle space-time aspects will be almost absent in our treatment. Newton theory becomes essentially realistic and viable when multiparticle systems are analyzed. It is just there where metrical concepts become almost unavoidable, because it is practically impossible to construct any realistic model of interparticle forces without the explicit use of the metric tensor. Extended bodies are described as discrete or continuous systems of material points. Their motion consists of that of the center of mass, i.e., translational motion and the relative motion of constituents with respect to the center of mass. The total configuration space may be identified with the Cartesian product of the physical space (translational motion) and the configuration space of relative motion. In many physical problems the structure of mutual interactions leads to certain hierarchy of degrees of freedom of the relative motion; in particular, some constraints may appear. The effective configuration space becomes then the Cartesian product ot the physical space and some manifold of additional degrees of freedom. There are situations when this auxiliary manifold and the corresponding dynamics are postlulated as something rather primary then derived from the multiparticle models. Usually the guiding hints are based on some symmetry principles. In this way the concept of internal degrees of freedom replaces that of relative motion. Sometimes it is a merely convenient procedure, but one can also admit something like essentially internal degrees of freedom not derivable from any multiparticle mode. After all, the very concept of the material point is an abstraction of a small piece of matter.

8

Invariant geodetic systems on Lie groups and affine models of internal and collective degrees of freedom

Sławianowski J. J., Kovalchuk V., Sławianowska A., Gołubowska B., Martens A., Rożko E. E., Zawistowski Z. J.

Prace Instytutu Podstawowych Problemów Techniki PAN

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2004

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nr 7

3-164

EN

In some of our earlier papers including rather old ones we have discussed the concept of affinely-rigid body, i.e., continuous, discrete, or simply finite system of material points subject to such constraints that all affine relations between its elements are frozen during any admissible motion. For example, all material straight lines remain straight lines in the course of evolution, and their parallelism is also a constant, non-violated property. Unlike this, the metrical features, like distances and angles, need not be preserved. In other words, such a body is restricted in its behaviour to rigid translations, rigid rotations, and homogeneous deformations. Models of this kind may be successfully applied in a very wide spectrum of physical problems like nuclear dynamics (droplet model of the atomic nuclei), molecular vibrations, macroscopic elasticity (in situations when the length of excited waves is comparable with the size of the body), in the theory of microstructured bodies (micromorphic continua), in geophisics (the theory of the shape of Earth), and even in large-scale astropysics (vibrating stars, vibrating concentrations of the cosmic substratum, like galaxies or concentrations of the interstellar dust).