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Wyszukujesz frazę "High field" wg kryterium: Temat


Wyświetlanie 1-8 z 8
Tytuł:
Analysis of the power losses in the three-phase high-current busducts
Autorzy:
Szczegielniak, T.
Piątek, Z.
Kusiak, D.
Powiązania:
https://bibliotekanauki.pl/articles/97329.pdf
Data publikacji:
2015
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
high-current busduct
power losses
electromagnetic field
Opis:
This paper presents an analytical method for determining the power losses in the three-phase gas-insulated transmission line (i.e., high-current busduct) of circular cross-section geometry. The mathematical model takes into account the skin effect and the proximity effects, as well as the complete electromagnetic coupling between phase conductors and enclosures (i.e., screens). Apart from analytical calculation, computer simulations for high-current busduct system power losses were also performed with the aid of the commercial FEMM software, using two-dimensional finite elements.
Źródło:
Computer Applications in Electrical Engineering; 2015, 13; 21-27
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Power losses in the three-phase gas-insulated line
Autorzy:
Szczegielniak, T.
Kusiak, D.
Piątek, Z.
Powiązania:
https://bibliotekanauki.pl/articles/376150.pdf
Data publikacji:
2017
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
high-current busduct
electromagnetic field
power losses
Opis:
This paper presents an analytical method for determining the power losses in the three–phase gas–insulated line (i.e., high-current busduct) of circular cross–section geometry which phase conductors are placed in vertex of a square. The mathematical model takes into account the skin effect and the proximity effects, as well as the complete electromagnetic coupling between phase conductors and enclosures (i.e., screens). The power losses produced by high-current busducts are usually calculated numerically with the use of a computer. However, the analytical calculation of the power losses is preferable, because it results in a mathematical expression for showing its dependences on various parameters of the line arrangement. Moreover, knowledge of the relations between electrodynamics and constructional parameters is necessary in the optimization construction process of the high-current busducts.
Źródło:
Poznan University of Technology Academic Journals. Electrical Engineering; 2017, 89; 89-98
1897-0737
Pojawia się w:
Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gęstość prądu przewodów drążonych o przekroju prostokątnym
The current density of a rectangular hollow bus conductor
Autorzy:
Kolańska-Płuska, J.
Powiązania:
https://bibliotekanauki.pl/articles/153333.pdf
Data publikacji:
2013
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
tor wielkoprądowy
pole elektromagnetyczne
high current bus
electromagnetic field
Opis:
W pracy przedstawiono algorytm wyznaczania rozkładu gęstości prądu szynoprzewodów drążonych o przekroju prostokątnym stosowanych do zasilania wzbudnika wewnętrznego nagrzewnicy indukcyjnej do hartowania powierzchniowego wsadów rurowych. Algorytm zaimplementowano w programie komputerowym do projektowania torów wielkoprądowych. Otrzymane wyniki rozkładu gęstości prądu porównano z wynikami obliczeń metodą elementów skończonych w przestrzeni 2D w ogólnodostępnym pakiecie do modelowania pola. Wielowariantowa analiza rozkładów gęstości prądu w szynach umożliwiła wyznaczenie parametrów geometrycznych toru jak grubość czy rozstaw szyn, tak aby straty mocy w torze były najmniejsze.
This paper presents an algorithm for determining the distribution of current density of a rectangular hollow bus conductor used to supply the internal inductor of an induction heater for surface hardening of tube feedstock. The algorithm was implemented in a computer program used for calculations. The calculation results of the current density distribution were compared with those obtained by the finite element method in 2D space with a common calculation package. Multivariate analysis of the current density distribution in the bus conductors enabled determining the line geometric parameters such as the thickness or spacing of the bus conductors, so that the power losses in the line were as little as possible. A Fredholm integral equation of second kind (2) was formulated taking into account the proximity effect. The method for approximation of the integral operator in equation (2) using a combination of standard functions (10) gives rise to its exact algebraisation without repeated references to the numerical integration procedure in determining the coefficients (4). It is also important due to the minimization of the total computation time. It is proved that the matrix of integral equation (4) with elements (10) can be used to determine own and mutual impedances of rectangular bus conductors with taking into account the skin and proximity effects. For this purpose, there is realized a sequence of transformations of matrix (12) in (14) (16) (19) and (20). Finally, there is obtained equation (21) determining the total impedance of the bus conductor.
Źródło:
Pomiary Automatyka Kontrola; 2013, R. 59, nr 10, 10; 1076-1079
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Power losses in the screens of the flat single-pole high-current busduct
Autorzy:
Szczegielniak, T.
Piątek, Z.
Kusiak, D.
Powiązania:
https://bibliotekanauki.pl/articles/97698.pdf
Data publikacji:
2013
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
analytical method
high-current busduct
electromagnetic field
power losses
Opis:
This paper presents an analytical method for determining the power losses in the screens of the three-phase gas-insulated transmission line (i.e., high-current busduct) of circular crosssection geometry. The mathematical model takes into account the skin effect and the proximity effects, as well as the complete electromagnetic coupling between phase conductors and enclosures (i.e., screens). The power losses produced by high-current busducts are usually calculated numerically with the use of a computer. However, the analytical calculation of the power losses is preferable, because it results in a mathematical expression for showing its dependences on various parameters of the line arrangement. Moreover, knowledge of the relations between electrodynamics and constructional parameters is necessary in the optimization construction process of the high-current busducts.
Źródło:
Computer Applications in Electrical Engineering; 2013, 11; 64-72
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on the operational performance of high speed permanent magnet generator with controlled rectifier in distributed generation
Autorzy:
Hongbo, Q.
Yanqi, W.
Cunxiang, Y.
Kaiqiang, H.
Powiązania:
https://bibliotekanauki.pl/articles/140696.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high speed permanent magnet generator
controlled rectifier
electromagnetic field
switching frequency
Opis:
The uncontrolled rectifier and controlled rectifier which use fixed switching frequency control strategy are applied usually during the working of a high-power high- speed permanent magnet generator (HSPMG). Even for the controlled rectifier, it will generate harmonics. The electromagnetic performance of the HSPMG is also affected by these harmonics. In this paper, the influences of the fixed switching frequency control strategy on a HSPMG were studied. Based on the Fourier theory, the harmonic currents of the generator were analyzed, and the change of harmonic distribution range and current total harmonic distortion (THD) were obtained. By using an indirect field-circuit coupling method, the influences of the fixed switching frequency control strategy on the losses and torque of the generator were analyzed. The relations between the switching frequency and the losses and torque of the generator were obtained, and the change mechanism of the loss was revealed. The obtained conclusions can provide reference for the optimized choice of the switching frequency of the distributed generation system with the HSPMG. It can also provide support for the HSPMG electromagnetic structural optimization and the optimization of the loss and harmonic on the system level.
Źródło:
Archives of Electrical Engineering; 2018, 67, 4; 899-913
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fluctuations of electromagnetic field components under high voltage lines
Autorzy:
Paś, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/24202387.pdf
Data publikacji:
2021
Wydawca:
Centrum Rzeczoznawstwa Budowlanego Sp. z o.o.
Tematy:
high voltage lines
HV
electromagnetic field
EMF
waveform signals
linie wysokiego napięcia
pole elektromagnetyczne
sygnały falowe
Opis:
High voltage (HV) Lines are part of the national electricity system. They are used for electrical power distribution between the power plant and the recipient. In addition to fulfilling this function, they generate unintentional electromagnetic field (EMF). In order to reduce the field impact on animate and inanimate objects it used to be determined under HV lines protection zones and technological. During electricity transmission occur PEM interferers, which process is dependent on changes e.g., voltage dips, short interruptions or in system. Voltage and current in changes the line superimpose on the alternating electromagnetic field produced by the HV lines and form a modulated waveform signals of different frequencies (50 Hz fundamental frequency, interharmonics and harmonics systems).
Źródło:
Modern Engineering; 2021, 4; 13--20
2450-5501
Pojawia się w:
Modern Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Fields of Induction Heaters in the Framework of Directive 2004/40/EC of the European Parliament and of the Council
Autorzy:
Decat, G.
Deckx, L.
Meynen, G.
Powiązania:
https://bibliotekanauki.pl/articles/89978.pdf
Data publikacji:
2006
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
electromagnetic field
occupational exposure
high exposure sources
mitigation
pole elektromagnetyczne
pole magnetyczne
prawo
prawo pracy
urządzenia grzewcze
ekspozycja
dyrektywa 2004/40/WE
Opis:
The spectrum and the polarization of the magnetic flux density (B-field) of 6 induction heaters and 1 arc oven were measured by means of a PMM (Italy) spectrum analyser. The spectrum analysis showed that no substantial harmonics were observed while the polarization analysis revealed that the operator’s exposure was non-homogeneous within a distance of 1.5 m from the heater. When the distance was larger, the body was homogeneously exposed. In general we can state that the B-field strongly varied between heaters and that exposure exceeded the occupational reference levels recommended by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) (1998) and European Directive 2004/40/EC in 5 of the 7 heaters. Within the framework of the Directive some protection actions should be taken. Whereas mitigation of existing/old induction ovens is difficult, the design of new induction heaters and their housing should be based, among others, on electromagnetic reducing engineering concepts.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2006, 12, 2; 169-176
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hazards of electromagnetic radiation
Zagrożenia przez promieniowanie elektromagnetyczne
Autorzy:
Jeleński, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/1831407.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Materiałów Elektronicznych
Tematy:
electromagnetic field
high voltage power lines
mobile phone base stations
mobile phones
radio and TV transmitters
household appliances
leukaemia
brain tumours
pole elektromagnetyczne
linie wysokiego napięcia
stacje bazowe telefonii komórkowej
telefony komórkowe
nadajniki radiowe i TV
sprzęt AGD
białaczka
nowotwory mózgu
Opis:
After a brief overview of the nature of electromagnetic (EM) radiation and its sources, the article presents selected findings concerning the risks caused by low-frequency EM fields emitted by 50 Hz high-voltage power lines and home appliances. These sources of radiation affect mainly the nervous system and may contribute to the development of cancer. On the other hand, the impact of high frequency EM fields emitted by radio and television transmitters, and mobile phones originate mainly from dielectric losses leading to body heating (thermal hazards) as well as from some non-thermal hazards, which have been less extensively investigated. The remote consequences include: auditory and behavioural effects, blood-brain barrier disruption and cancer. The examples of the recommendations and standards developed by the international and national organizations are also presented.
Po krótkim omówieniu źródeł i charakteru promieniowania elektromagnetycznego przedstawiono wybrane wyniki badań zagrożeń powodowanych przez pola EM niskiej częstotliwości emitowane przez linie energetyczne wysokiego napięcia 50 Hz i sprzęt AGD. Ich głównym efektem jest oddziaływanie na układ nerwowy i wpływ na choroby nowotworowe. Z kolei efektem pól EM wysokich częstotliwości emitowanych przez nadajniki radiowe, telewizyjne, telefony komórkowe są głównie straty dielektryczne prowadzące do nagrzewania ciała (zagrożenia termiczne) oraz słabiej zbadane zagrożenia nietermiczne. Do tych ostatnich należą: efekty słuchowe, behawioralne, zakłócenia działania bariery krew-mózg, choroby nowotworowe. Przedstawiono również przykłady zaleceń i norm opracowanych przez międzynarodowe i krajowe organizacje.
Źródło:
Materiały Elektroniczne; 2020, T. 48, nr 1-4, 1-4; 3-14
0209-0058
Pojawia się w:
Materiały Elektroniczne
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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