ELEKTRONIKA, ENERGETYKA, ELEKTROTECHNIKA ›
PRZEGLĄD ELEKTROTECHNICZNY ›
2008-11 |
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Analytical approximation of dynamic hysteresis loops
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Zdzisław WŁODARSKI 
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Presented model results from the general properties of hysteresis curves. Quasi-static hysteresis is described by analytical first-order reversal
curves using constant parameters. Approximate dependence of coercivity parameter on frequency and field amplitude extends modeling to
dynamic processes.
Streszczenie. Proponowany model wynika z ogólnych własności krzywych histerezy. Quasi-statyczna hi[...]
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Electric power system reliability optimization
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Józef PASKA
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Reliability is one of the most important criteria, which must be taken into consideration during planning and operation phases of
an electric power system, especially in present situation of the power sector. This paper considers the optimization of electric power system
reliability. The formalization of description of electric power system reliability level optimization is done as well as its p[...]
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Energy effectivity in fan and series motor aggregate
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Andrzej KUŁAKOWSKI Mirosław WCIŚLIK
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The paper deals with a mathematical model of a sucking aggregate. The parameters of the aggregate has been identified. The model
parameters depends on the angle of rotor rotation related to stator and number of shorted commutator segments. There has been worked out a
simulation model of the aggregate, also there have been carried out verifying research. A simulation analysis of the power loss in[...]
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Fuzzy modelling of chosen electroheat systems
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Jacek KUCHARSKI
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In the paper the method of application of fuzzy sets and fuzzy logic for modelling of distributed-parameter systems has been developed,
thermal systems in particular are of interest. Fuzzy techniques make it possible to include within a model specific properties of the plant expressed
in the form of a linguistic description. The work is focused on a certain class of electroheat systems - chamber[...]
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Generator indukcyjny przy niesymetrycznym obciążeniu
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Jerzy HICKIEWICZ Józef MOCH
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Przedstawiono modele matematyczne generatorów indukcyjnych przy pracy na wydzielone, asymetryczne obciążenie. Opracowano
również modele uwzględniające nieliniowość głównego obwodu magnetycznego. Zaprezentowano przykładowe wyniki badań symulacyjnych w
różnych stanach pracy generatora, np. przebiegi dynamiczne przy skokowej zmianie obciążenia oraz zewnętrzne charakterystyki statyczne przy
niesyme[...]
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Human body impedance in climatically bad conditions
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Stefan GIERLOTKA
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The aim of this study was to analyse the influence of the climate's difficult conditions on the human body impedance. The impedance of
the human body has been measured and analysed statistically. We evaluated the body's impedance for typical shock paths and certain climatic
conditions. Environmental conditions have been determined by means of a katathermometer. Using a regression fun[...]
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Improved Shunt Active Power Filters
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Krzysztof Piotr SOZAŃSKI
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This paper describes a shunt active power filters (APF) with improved dynamic performance. When the value of load current changes
rapidly, the APF transient response is too slow. This distortion causes an increase of harmonic content in the line current, which is dependent on a
time constant. In the proposed circuit transient performance of APF is improved using non-causal predictive current com[...]
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Loading torque in tests of low-power drive system
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Janusz IGIELSKI
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The paper considers a problem of representing load introduced by mechanisms of low-power mechatronic devices. There was determined
an influence of the behaviour of electromagnetic friction brakes (which are applied for this purpose) on the accuracy of representing the variable of
torque fluctuation as expected during experimental studies. Specific features and behaviours of disc and powder brake[...]
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Modelling the temperature homogeneity of the glass melt obtained by EM action
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Mathematical model of semi-transparent melt flow, which is caused by thermal and EM convection, has been developed. Impact of
thermal boundary conditions and absorption coefficient on the temperature distribution of the melt has been analysed numerically. It has been shown
that convective and radiative heat transfer influence melt’s temperature distribution significantly and can both: incr[...]
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New Control System of the Shunt Active Power Filter
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Daniel WOJCIECHOWSKI Ryszard STRZELECKI
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The paper presents the control system of shunt active power filter (APF) with predictive reference current calculation and model based
predictive current control. The novel estimator and predictor of grid emf is proposed for AC voltage sensorless operation of APF. Proposed control
system provides control of APF current with high precision and dynamics limited only by APF circuit parameters. Ther[...]
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Power loss comparison for the ARCP resonant inverter regard to control method
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Sławomir KARYŚ
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W artykule przedstawiono analizę matematyczną strat mocy w rezonansowym przekształtniku biegunowym typu ARCP, w zależności
od zastosowanej metody sterowania. Porównano klasyczną metodę sterowania o stałych zależnościach czasowych dla sygnałów sterujących
z metodą, w której czas trwania sygnałów sterujących zależy od wartości chwilowej prądu obciążenia. Pokazano, że dzięki zastosowaniu drugiej
m[...]
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Przekształtniki wielopoziomowe typu FLC do zastosowań trakcyjnych
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Tadeusz PŁATEK
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Artykuł omawia problemy związane z załączaniem wielopoziomowego przekształtnika z tzw. kondensatorami o zmiennym potencjale
(Flying Capacitor Converter) do źródła napięcia zasilającego, jak również metodę stabilizacji napięć na kondensatorach poziomujących - w stanach
skokowej zmiany tego napięcia. W artykule podano wyniki badań symulacyjnych dla trzech układów przekształtników oraz wyniki badań[...]
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Steady states analysis of micro-grids operation
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Krzysztof KSIĘŻYK Mirosław PAROL
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Short characteristics of micro-grid and results of computer simulations of exemplary micro-grid operation in steady states have been
presented in the paper. Micro-grid operation, for different variants of micro-sources and battery energy storage operation, has been shown. In order
to carry out computer simulation of micro-grid operation specialized software has been used. Influence of micro-sour[...]
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Sterowanie samowzbudnym generatorem indukcyjnym
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Andrzej KASPROWICZ
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W artykule przedstawiono rozwiązanie oraz wyniki badań symulacyjnych sterowania samowzbudnym generatorem indukcyjnym dla
potrzeb autonomicznej elektrowni wiatrowej. Przedstawiono opracowany układ niezależnej regulacji składowej biernej oraz czynnej prądu stojana
generatora. Prezentowany układ umożliwia utrzymanie stałej wartości napięcia wyjściowego generatora niezależnie od zmian obciążenia. W
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Use of EM fields in production processes for PV cells
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Bernard NACKE
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The use of EPM technologies is well known in conventional applications like metal melting, casting and treating. In the last years EPM
methods with the use of electromagnetic fields were developed also for the semiconductor production in crystal growing for microelectronic but also
for photovoltaic (PV) applications. The paper shows two actual applications of EM fields in production processes fo[...]
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Use of frequency control to optimize induction axle scan hardening
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Valentin NEMKOV Robert GOLDSTEIN
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The paper is a continuation of the optimal design analysis of scanning process and inductors for scan hardening of axles that had been
reported in 2007 in two publications [1,2] and in presentation at a conference HES-07 in Padua, Italy. Improvements based on coil optimization at
two (1 and 3 kHz) have been reported in these presentations. Current article describes what additional improvements m[...]
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Voltage transformer operation in connection with the power quality
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Michał KACZMAREK Artur SZCZĘSNY
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Conductive disturbances in the supplying voltage may affect the root mean square voltage and shape of the voltage curve on the mains
which reflect in degradation of the power quality. The object of the article is the discussion of the results of the laboratory studies of the transmission
of conductive disturbances from primary side of the voltage transformer to the secondary side and inversely.
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Weak conducting material melt flow in crossed EM fields
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Andris JAKOVICS Vadims GEZA Bernd HALBEDEL
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New equipment for electromagnetic processing of weak conducting material melts was numerically investigated. Significance of different
effects and physical phenomena was evaluated. Complicated melt flow structure was obtained at specific equipment parameters.
Streszczenie. Nowe wyposażenie do elektromagnetycznego przetwarzania kąpieli materiałów słabo przewodzących zostało przebadane w drodze
a[...]
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Wirtualne laboratorium - realny element kształcenia
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Rozsądne wykorzystanie wszystkich dostępnych zasobów sprzętowych i programowych technologii informacyjnej jako elementów
edukacji, może niezwykle uatrakcyjnić proces kształcenia. Z punktu widzenia członka zbiorowości akademickiej powstaje pytanie: Jak najlepiej
wykorzystać nowe narzędzia technologii informacyjnej w samokształceniu, badaniach naukowych i w procesie dydaktycznym? Próba odpowiedzi [...]
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