Volume 2, Number 1 (2012)

REMOTE CONTROL MEASURING SYSTEM BASED ON STRAIN SENSORS

Anatoliy Druzhynin, Yuriy Khoverko, Ihor Ostrovkyi, Roman Koretskyi, Stepan Nichkalo
Lviv Polytechnic National University
druzh@polynet.lviv.ua

Abstract: The paper describes an automated wireless monitoring system developed for stress-strain state of main pipelines. Since the most damages occur in the main pipelines’ areas of intense plastic deformation, their remote control in such areas is of significant interest, and one of the solutions to the problem is the proposed measuring system based on Si-whisker sensitive elements.
Key words: whisker, deformation, automated system.

Кількість посилань 6

PRINCIPLES OF CONSTRUCTION AND APPLICATION OF MICROWAVE SYSTEMS FOR WIRELESS ENERGY TRANSMISSION OF GROUND AND SPACE BASING

Andrei Gomozov, Vladimir Shokalo, Dmitry Gretskikh, Shamil Fadel Alvan Al-Samarai
Kharkiv National University of Radioelectroniks
andgom@rambler.ru

Abstract: The results of the investigations, carried out in Kharkiv National University of Radio Electronics, into the principles of construction of modern microwave systems for wireless energy transmission (WET) on the basis of a multipositional system of radiators (MSR) with focusing of single-stage discrete V-shaped multifrequency signals and a circular polarization rectenna, are presented.
Two versions of such systems are considered: one system is intended for power supply of ground-based remote regions, the second system is intended for energy supply of low-orbit small-size (LS) space vehicles (SV).
Кey words: wireless energy transmission, rectenna, multipositional system of radiators, electromagnetic radiation focusing, remote object, low-orbit space vehicle.

Кількість посилань 6

VOLTAGE CONTROL IN THE STATOR CIRCUIT OF CAGE INDUCTION MACHINE OPERATING AS GENERATOR IN SMALL SCALE HYDROPOWER PLANT

Andrzej Kandyba1, Marian Kalus2, Igor Piotr Kurytnik3
1Department of Power Electronics, Electrical Drives and Robotics, Faculty of Electrical Engineering, Silesian University of Technology,
2Institute of Innovative Technologies Emag, Poland,
3Department of Electrical Engineering and Automation University of Bielsko-Biała
ikurytnik@ath.bielsko.pl

Abstract: The synthesis of RMS voltage control system in the stator circuit of squirrel cage induction machine based on the linear criterion of " optimum magnitude" by C. Kessler 'a was performed. The squirrel cage induction machine was operating as a generator in autonomous (isolated) network. Induction machine is driven by an induction machine supplied from the inverter, which simulates the low pressure head water turbine. Synthesis process of the control system was supported by experimental studies of this system.
Key words: Small hydroelectric power plant, asynchronous generator, isolated grid, control system.

Кількість посилань 5

IMPROVING THE EFFICIENCY OF ELECTRONIC MONITORING SYSTEMS AT POTENTIALLY HAZARDOUS OBJECTS BASED ON OPTIMIZATION OF GROUP SENSORS

Borys Pospelov1, Roman Shevchenko1, Andriy Balan2
1National University of Civil Protection in Ukraine,
2Representative Office of Leica Geosystems AG

Abstract: A method for improving the efficiency of electronic monitoring systems based on the usage of group sensors for detecting critical conditions at potentially hazardous objects has been described. The problem of determining the optimal Bayesian majority rule of detection for group sensors has been solved. It has been shown that for group sensors the threshold and the majority rule of detection must be optimized jointly. The task of joint optimization of the threshold and the majority rule has been solved. The estimation of an expected gain as a result of using an optimized group sensor, that shows its high detecting efficiency, has been carried out.
Key words: electronic monitoring system of potentially hazardous objects, group sensor, critical state of an object, critical state detection indicator.

Кількість посилань 3

MODELLING OF TEMPERATURE CONDITIONS IN ELECTRICAL DEVICES OF INHOMOGENEOUS STRUCTURE

Dmytro Fedasyuk, Vasyl Gavrysh
Lviv Polytechnic National University
fedasyuk@lp.edu.ua

Abstract: Mathematical modelling of heat exchange processes for an electric device of inhomogeneous structure and the analytical numerical estimate of the relevant boundary problem of heat conduction have been considered.
Key words: temperature, heat conduction, steady-state, isotropic, heat dissipation, ideal thermal contact, foreign reach-through thermo-active inclusion.

Кількість посилань 11

CURRENT DIFFERENTIAL RELAY WITH FAULT LOCATION AND SYNCHRONISATION OF MEASUREMENTS FUNCTIONS

Eugeniusz Rosolowski1, Jan Izykowski1, Murari Mohan Saha2
1Wroclaw University of Technology, Institute of Electrical Power Engineering, Wroclaw, Poland,
2ABB AB, Västerås, Sweden
eugeniusz.rosolowski@pwr.wroc.pl

Abstract: This paper considers a fault location and an analytical synchronisation of two-end measurements functions as embedded into a current differential protective relay. As a result of that, incomplete two-end measurements, i.e. a three-phase current measured at both line ends, while a three-phase voltage only from one end are considered as the input signals. The fault location and synchronisation formulae are derived with considering a distributed-parameter model of a transposed overhead line. The performed ATP-EMTP based evaluation has proved the validity of the presented algorithms and their high accuracy.
Key words: overhead power line, current differential relay, fault location, two-end measurement, analytic synchronisation, ATP-EMTP software.

Кількість посилань 7

MULTILAYERED SENSOR STRUCTURES FOR INTELLIGENT CONLROL SYSTEMS

Halyna Klym, Yuriy Kostiv
Lviv Polytechnic National University
klymha@yahoo.com, yura.kostiv@gmaol.com

Abstract: A multifunctional sensor system using multilayered thick-film sensor structures based on spinel-type NiMn2O4-CuMn2O4-MnCo2O4 manganites and magnesium aluminate MgAl2O4 has been developed. The technological peculiarities of making nanostructured sensors have been represented. The circuit diagram of the monitoring system using nanostructured sensors and a microprocessor for signal processing has been proposed. This system can be successfully applied for intelligent monitoring and controlling environment.
Key words: sensor structure, environment, thick film, microprocessor system.

Кількість посилань 8

MODELING OF DYNAMICAL REGIMES OF TWO-MOTOR ELECTRICAL DRIVES WITH DUE REGARD FOR ELASTICITY AND GAPS OF MECHANICAL TRANSDUCERS

Jumber Dochviri, Oleg Khachapuridze
Department of Electrical Engineering of Georgian Technical University
Jumber_Dochviri@yahoo.com

Abstract: In the paper a mathematical model of two-motor electrical drive with one speed controller and two thyristor converters, by taking into account elasticity's and gaps of mechanical transducers, has been constructed. By using state-space methods, the transfer functions of the object have been determined. Some recommendations for tuning of the regulators have been suggested. Dynamical characteristics that are near to the optimal ones have been obtained by applying MATLAB.
Key words: dynamics, two-motor electrical drive, modeling.

Кількість посилань 6

CONSTRUCTION OF INVARIANT DIFFERENCE AND DISCRETE ANALOGUES OF DIFFERENTIAL OPERATORS OF HIGH ORDER DISCRETIZATION ERROR

Mariya Howykowycz
Lviv Polytechnic National University
howykowycz@ieee.org

Abstract: The paper offers the algorithm of construction of difference and discrete analogues of differential operators on the basis of invariant approximations methodology. The reciprocal Taylor’s matrix of the 6-th degree has been calculated in exact figures what allows us to construct difference and discrete analogues of high order discretization errors.
Key words: invariant approximation, difference analogue, discrete analogue, discretization error.

Кількість посилань 3

SERVICE-ORIENTED RESOURCE PLANNING FOR MULTISERVICE IP NETWORKS

Mykhailo Klymash, Orest Lavriv, Bohdan Buhil
Lviv Polytechnic National University
lavriv@polynet.lviv.ua

Abstract: This work proposes the analysis of service quality parameters for packet networks. The algorithm of packet processing has been developed. Research into delay and jitter for the proposed processing method has been carried out.
Key words: self-similar traffic, traffic distribution system, simulation.

Кількість посилань 5

PROPERTIES OF PROBABILITY PRODUCTIVE DEPENDENCIES IN THE DATA ANALYSIS OF LARGE DATA VOLUMES

Oleksandr Pshenychnyi
Lviv Polytechnic National University
sasha.pshenychniy@gmail.com

Abstract: This paper describes findings in the area of aggregated associative dependencies detection. The work gives a method of building aggregated associative dependencies in large data volumes. This research can be applied to the wide range of data types and optimize data mining processes
Key words: aggregated associative dependency, data mining, large data volume, functional dependency.

Кількість посилань 7

A TWO-DIMENSIONAL MODEL OF AN ELECTROMAGNETIC ACCELERATOR

Orest Hamola, Marta Hamola
Lviv Polytechnic National University
oresthamola@polynet.lviv.ua

Abstract: The mathematical model of an accelerator’s magnetic field, which takes into account its symmetry, the nonlinearity of an armature characteristic B(H), and eddy currents, has been investigated. The model has been developed on the basis of the finite elements method. The armature that moves under the applied Ampere’s force has been represented as a movable distribution of magnetic permeance.
Key words: coil, eddy currents, electromagnetic accelerator, ferromagnetic core (armature).

Кількість посилань 7

LINEAR-MODE OPERATION OF A HIGH-ORDER SINGLE-BIT SIGMA-DELTA MODULATOR

Roman Kochan
Lviv Polytechnic National University
kochan.roman@gmail.com

Abstract: This paper considers a simulation mathematical model of a high-order single-bit sigma-delta modulator. Both the condition and the criterion of this modulator operation in a linear mode have been formulated.
Key words: high-order sigma-delta modulator, linear-mode operation, simulation model.

Кількість посилань 9

COMPUTATION OF POSITIVE STABLE REALIZATIONS FOR DISCRETE-TIME LINEAR SYSTEMS

Tadeusz Kaczorek
Faculty of Electrical Engineering, Bialystok University of Technology, Poland
kaczorek@isep.pw.edu.pl

Abstract: Sufficient conditions for the existence of positive stable realizations for given proper transfer matrices are established. Two methods are proposed for determination of the positive stable realizations for given proper transfer matrices. The effectives of the proposed procedures is demonstrated on numerical examples.
Key words: computation, initial condition, observability, positive, discrete-time, linear, system

Кількість посилань 16

IMPROVED SOLUTION OF CRAMER-RAO LOWER BOUND FOR TOA/RSS LOCALIZATION

Taras Holotyak1, Serhiy1 Voloshynovskiy1, Jose Rolim1, Ivan Prudyus2
1Department of Computer Sciences, University of Geneva, Switzerland
2Institute of Telecommunications, Radioelectronics and Electronic Engineering,
Lviv Polytechnic National University, Ukraine
{Taras.Holotyak, svolos, Jose.Rolim}@unige.ch, iprudyus@lp.edu.ua

Abstract: In this paper the problem of evaluation of the bound accuracy for range based localization techniques in wireless sensor networks is considered. The comprehensive analysis of the existing solution of the Cramer-Rao lower bound problem for the anchored localization based on the time of arrival or relative signal strength principles shows certain discrepancy between an analytical solution and simulation results. Therefore, a new bound for this problem has been developed on the basis of more accurate stochastic modeling of the localization error.
Key words: localization, Crame-Rao lower bound, wireless sensor networks.

Кількість посилань 12

SYMMETRY OF DIFFERENTIAL EQUATIONS OF ELECTROMAGNETIC FIELD IN IMMOVABLE MEDIUM

Vasyl Tchaban
Lviv Polytechnic National University
vtchaban@polynet.lviv.ua

Abstract: In the paper it is shown that differential equations describing an electromagnetic field in solid immovable media based on the vectors of intensities of electric or magnetic fields in most cases practically coincide with those based on the vector-potential of the electromagnetic field. This special feature essentially simplifies practical analysis, beginning with the determination of border conditions. The expressions for static and differential parameters of the medim are given.
Key words: differential equations, vectors and vector-potential of electromagnetic field, non-linearity, anisotropy, static and differential parameters, symmetry.

Кількість посилань 17

SEARCHING THE RELEVANT PRECEDENTS IN DATASPACES BASED ON ADAPTIVE ONTOLOGY

Vasyl Lytvyn1, Natalya Shakhovska1, Volodymyr Pasichnyk1, Dmytro Dosyn2
1Lviv Polytechnic National University, 2Karpenko Physico-Mechanical Institute of NASU
vasyl17.lytvyn@gmail.com

Abstract: This document reviews the functioning of the intellectual agents based on adaptive ontology, which are using precedents. Also was made the software activity of such agents.
Key words: data space, intelligent agent, ontology, precedent

Кількість посилань 7

INVESTIGATION OF THE INFLUENCE OF CAPACITOR IN THE EXCITATION WINDING CIRCUIT OF A SYNCHRONOUS MOTOR ON ITS STARTING TORQUE

Vasyl Malyar, Iryna Dobushovska
Lviv Polytechnic National University
svmalyar@polynet.lviv.ua, i.dobushovska@gmail.com

Abstract: The problem of mathematical modelling the asynchronous modes of synchronous motors with a capacitor in the excitation winding circuit is discussed. A technique for studying the effect of capacitance value on the starting torque of the motor has been proposed. The task has been solved as a boundary value problem for a non-linear system of power balance equations, in which the magnetic flux linkage is calculated on the basis of the magnetic field computation using the magnetic circuit theory.
Key words: synchronous motor, starting torque, capacitor, boundary value problem.

Кількість посилань 7

SWITCHED RELUCTANCE MOTOR WITH BUFFER OF ENERGY AND ITS MATHEMATICAL MODEL

Vasyl Tkachuk
Lviv Polytechnic National University
tkachuk@polynet.lviv.ua

Abstract: the constructive schemes of a switched reluctance motor and the circuit diagrams of a commutator with capacity buffers of energy have been suggested. The mathematical model of carrying out the investigation of electromechanical processes occurring in electric drives with a switched reluctance motor with buffers of energy has been presented.
Key words: switched reluctance motor, capacity buffer of energy, salient poles.

Кількість посилань 9

CONTROL OF CHARGE OF SUPERCAPACITOR’S BATTERY AS DEVICE WITH DIFFUSION PROPERTIES

Victor Busher
Odesa National Polytechnic University

Abstract. There has been analyzed the charge processes in a battery of series-connected supercapacitors and developed the fractional differential-aperiodic regulator for a model of fractionally-integrated section for SIMULINK with high accuracy and fast performance at the fixed calculation step. The proposed model is an improved version of the supercapacitor that takes into consideration the diffusive processes and parameters’ variation on change of the current polarity.
Key words: control, supercapacitor’s battery.

Кількість посилань 5

MODELLING OF ELECTRODYNAMIC PROPERTIES OF STRUCTURES WITH N-MULTIPLE PERIODICITY

Volodymyr Pavlysh, Viktor Hoblyk, Iryna Nychai, Oleksij Liske
Lviv Polytechnic National University
viktor_hoblyk@mail.ru

Abstract: In this paper, mathematical models of electromagnetic structures with N – multiple periodicity represented as branched continued fractions are described; the results of the investigation of the peculiarities of an electromagnetic field formed by a dielectric plate with the complex modulation of its dielectric permittivity are shown; the results of research of electrodynamic properties of modulated circular impedance cylinder are presented.
Key words: structures with N – multiple periodicity, branched continued fractions, mathematical models, the spatial field distribution.

Кількість посилань 18

SCANNING TELEVISION OPTICAL MICROSCOPE FOR BIOLOGICAL MICROOBJECTS RESEARCH

Volodymyr Shkliarskyi, Ivan Prudyus, Anatoliy Pedan
Lviv Polytechnic Notional University
shkliarskyi@polynet.lviv.ua

Abstract: Ways of developing a scanning television microscope, which can be used for the investigation of biological microobjects, have been analyzed. The capabilities of the microscope are extended due to a raster formation in the television mode and little-frame mode. Ways of changing the raster size while maintaining the microobject image resolution have been proposed.
Key words: Scanning microscope, electron beam tube, microobject.

Кількість посилань 10

NEW POSSIBILITIES OF MONITORING ELECTRIC POWER QUALITY BY MEANS OF WAVELET-TRANSFORM APPARATUS

Volodymyr Vanko, Petro Stolyarchuk
Lviv Polytechnic National University
vvm@lp.edu.ua

Abstract: The problem of estimating various voltage disturbances in electric networks considering the enumeration of normative and recommended indices of electric power quality is under consideration. The differential wavelet-transform-based method of evaluating the processes of voltage changes caused by connecting up electrotechnical objects as well as algorithms of identifying those quality indices are proposed in the work enlightening the complete characteristic of the mentioned voltage change processes in networks.
Key words: electric energy, quality indices, voltage fluctuations and distortions, wavelet-transform.

Кількість посилань 15

CREATING ELECTRONIC DEVICE MACROMODELS BY QUADRATIC AND CHEBYSHEV APPROXIMATION

Yaroslav Matviychuk1, Peter Malachivsky2, Roman Hasko1
1Lviv Polytechnic National University,
2Leading researcher, Centre for Mathematical Modeling IAPMM National Academy of Sciences of Ukraine
matv@ua.fm, psmal@cmm.lviv.ua, r.hasko@gmail.com

Abstract: In the article the problem of mathematical macromodeling of electronic devices has been considered. The results of macromodeling by the least squares approximation and the Chebyshev approximation for frequency detectors, multivibrators, and oscillators have been shown. The efficiency of the method of least squares in reproducing the original signal macromodels of nonlinear electronic devices has been proved.
Key words: mathematical macromodeling, electronic devices, least squares and Chebyshev approximation.

Кількість посилань 5

THE ANALYSIS OF ELECTROMOTIVE FORCE APPEARANCE IN A LINEAR UNIPOLAR GENERATOR

Yaroslav Kovivchak
Lviv Polytechnic National University,
ya_kovivchak@yahoo.com

Abstract: On the basis of Lorenz transformation, the mathematical analysis of known results of practical research of a unipolar generator has been given. The analysis shows that the obtained experimental results have strict theoretical substantiation and they are not exceptions to the basic rules of transformation of vectors of an elec¬tromagnetic field into any inertial coordinate system. The necessary conditions for the appearance of electromotive force in unipolar generators of various constructions have been given.
Key words: Lorenz transformation, mathematical analysis, electromagnetic field, unipolar generator.

Кількість посилань 9

DISTRIBUTION OF CURRENT DENSITY ON THE PERIMETER OF A CYLINDRICAL CONDUCTOR OF A WAVEGUIDE’S VIBROEXCITER

Yosyp Zakharia
Lviv Polytechnic National University
12 S. Bandera Street, Lviv, 79013, Ukraine

Abstract: On the basis of electrodynamic analysis a considerable nonuniformity of the current density distribution on the perimeter of a cylindrical conductor of a waveguide exciter has been detected. It has been proved that the above mentioned nonuniformity mostly affects the input reactance of the exciter. Such effect is minimum at central location of the exciter in the waveguide. It rises sharply when the exciter is diplaced. Therefore, we come to conclusion that it is necessary to take into consideration the nonuniformity of the current density distribution when analyzing a vibroexciter.
Key words: waveguide vibroexciter, the connection: line – waveguide.

Кількість посилань 6

Syndicate content