Temat: magnetizing - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Wind Powered Electricity Generation Through Self Excited Induction Generator
Autorzy:: Chaturvedi, Yatender
Goel, Ankit
Tematy:: Magnetic saturation
Magnetizing reactance
Newton-Raphson method; Pokaż więcej
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Powiązania:: https://bibliotekanauki.pl/articles/1075571.pdf Link otwiera się w nowym oknie
Opis:: An iterative method is used to identify the saturated magnetizing reactance and the frequency of a self-excited induction generator for given capacitance, speed, and load in a systematic way. Under steady state, this procedure is effective in analyzing such systems. A correlation has been observed between the computational algorithm results & experimental outcomes. Under steady state condition, changes in various variables have been studies and the determination of the feasibility of such system is done.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Phase change of chlorite in reducing atmosphere
Autorzy:: Liu, X.
Yu, Y.
Chen, W.
Tematy:: chlorite
phase change
magnetizing
reducing roasting
magnetite; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/110704.pdf Link otwiera się w nowym oknie
Opis:: Magnetizing roasting is an important pre-treatment technique for beneficiation of hematite and limonite ores. Reduction mechanisms of these iron minerals have been fully studied while the mechanism of reduction of chlorite is not well understood. In this study, a reduction roasting study examining the phase change of chlorite with roasting temperature was undertaken. The major finding from this study was that chlorite partially was reduced to magnetite by carbon at 750 ⁰C, and the newly formed magnetite was finely disseminated within quartz and olivine. It was demonstrated that these locked magnetite particles would be reported to iron concentrate by low intensity magnetic separation resulting in high impurity content, especially SiO2 and Al2O3 contents in the concentrate.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Rotor flux oriented control of induction machine based drives with compensation for the variation of all machine parameters
Autorzy:: Extremiana, G.
Abad, G.
Arza, J.
Chivite-Zabalza, J.
Torre, I.
Tematy:: parameter on-line estimation
rotor flux oriented control
magnetizing curve
iron losses; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/202309.pdf Link otwiera się w nowym oknie
Opis:: The performance of rotor flux oriented induction motor drives, widely used these days, relies on the accurate knowledge of key machine parameters. In most industrial drives, the rotor resistance, subject to temperature variations, is estimated on-line due to its significant influence on the control behaviour. However, the rest of the model parameters are also subject to slow variations, determined mainly by the operating point of the machine, compromising the dynamic performance and the accuracy of the torque estimation. This paper presents an improved rotor-resistance on-line estimation algorithm that contemplates the iron losses of the electrical machine, the iron saturation curve and the mechanical losses. In addition, the control also compensates the rest of the key machine parameters such as the leakage and magnetizing inductances and the iron losses. These parameters are measured by an off-line estimation procedure and stored in look up-tables used by the control. The paper begins by presenting the machine model and the proposed rotor flux oriented control strategy. Subsequently, the off-line parameter measurement procedure is described. Finally, the algorithm is extensively evaluated and validated experimentally on a 15 kW test bench.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Pomiary parametrów materiałów magnetycznych przy alternatywnych wariantach wymuszenia sygnału magnesującego
Measurements of magnetic material parameters at alternative variants of magnetizing signal excitation
Autorzy:: Kwiczala, J.
Kolano-Burian, A.
Tematy:: materiał magnetyczny
sygnał magnesujący
pomiary magnetyczne
magnetic material
magnetizing signal
magnetic measurements; Pokaż więcej
Wydawca:: Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Powiązania:: https://bibliotekanauki.pl/articles/151264.pdf Link otwiera się w nowym oknie
Opis:: W artykule przedstawiono wyniki pomiarów parametrów próbek materiałów magnetycznych przy zastosowaniu różnych wariantów wymuszenia sygnału magnesującego. Sinusoidalne wymuszenie napięciowe sygnału powoduje sinusoidalne wymuszenie indukcji magnetycznej, co powoduje odkształcenie natężenia pola, natomiast sinusoidalne wymuszenie prądowe sygnału magnesowania powoduje sinusoidalne wymuszenie natężenia pola, co skutkuje odkształceniem indukcji (strumienia magnetycznego). Porównano parametry podstawowych parametrów opisujących właściwości materiałów magnetycznych badanych próbek otrzymane dla dwóch wariantów wymuszeń pola.
The parameters of magnetic materials are determined by both the autonomic measuring stands, i.e. the volt-ampermeter method and the impedances bridges or the computer measuring systems. The sources of signal in measuring system to investigation of magnetic material parameters are alternating current power supplies. However, in automated measuring systems, the final unit of track feeding is power amplifier. It permits to extorting both the proper value of voltage and to supply the tested sample appropriate large current. The Polish Standard allows two variants of sinusoidal signal ex-tortion to investigation of magnetic materials. First of them is sinusoidal extortion of magnetic flux density B while the second variant admits to sinusoidal signal extortion of field intensity H into the tested sample. Extortion from theoretically ideal voltage source signal corresponds to the first option, while in the second variant is necessary ideal current source. In practice, to comply with requirement of the Standard, it is necessary to assure the condition of a much smaller or a much larger internal source impedance in relation to impedance of magnetizing winding of the test sample, respectively to condition of voltage or current extortion. Disposing of either the power supply with well-known internal impedance or the amplifier with well-known output impedance this condition be comply with properly selection of magnetizing winding number of turns. The investigation of magnetic materials of different samples in which was executed either the force of sinusoidal magnetic flux density, which effects the deformation of intensity of the field strength or sinusoidal force of the field strength which causes the deformation of magnetic flux is presented. The essential parameters of the magnetic materials of the test samples to obtain by means of two variants input signal force were compared. The investigations showed distinctness of measurements results of parameters of the same samples by applying the different variants of signal extortions admitted by the Standard.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: An Experimental Set-up Involving Low-cost Digital Controller to Study the Magnetizing Inrush Current in a Transformer using Point-on-Wave Switching Technique
Autorzy:: Nayak, Ananya
Chatterjee, Dipankar
Dalapati, Suvarun
Tematy:: microcontroller
point on wave switching technique
zero-crossing detector
thyristor
transformer magnetizing current; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/58970756.pdf Link otwiera się w nowym oknie
Opis:: Generally in under-graduate studies, magnetizing inrush current (MIC) is discussed theoretically without giving much practical exposure. This paper presents the development of a low cost experimental set-up using a digital controller to study the MIC and the different parameters which can affect the same. This also helps to show how the inrush current can be minimized. This set-up also provides a hands-on experience of MIC and its control in under-graduate study, which can help an upcoming practitioner in industry as well as in further research. This paper presents a brief description of MIC, followed by a short analysis. Here, a pair of anti-parallel thyristors are connected in series with the primary winding of a single-phase power transformer. The turningon instant of this switch, with respect to the zero-crossing instant of the input supply voltage, may be adjusted through a firmware, in a PIC18F4620 from Microchip Technology microcontroller development board from Microchip Technology to control the transformer energisation instant. The firmware is developed in MPLABX-IDE from Microchip Technology, and the scheme is verified via simulations in Proteus simulation software. A suitable circuit to support the microcontroller development board to achieve the above function is designed and fabricated.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Effect of fluidized magnetizing roasting on iron recovery and transformation of weakly magnetic iron mineral phasein iron tailings
Autorzy:: Li, Wenbo
Han, Yuexin
Liu, Xiao
Shan, Yan
Li, Yanjun
Tematy:: iron tailings
fluidized magnetizing roasting
hematite
limonite
iron phase transformation
low intensity magnetic separation; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/110633.pdf Link otwiera się w nowym oknie
Opis:: The eastern tailings of the Anshan mining area are generally categorized as high silicon-bearing iron tailings, and the iron mainly exists in the form of hematite–limonite with an iron grade of 10.60%. In order to recover iron minerals and reduce the influence of the tailings on the environment, a method for pre-enrichment through the combination of low intensity magnetic separation and high intensity magnetic separation with fluidized magnetizing roasting and subsequent low intensity magnetic separation was developed to treat the eastern tailings of the Anshan mining area. The effects of gas-flow rate, H₂ concentration, roasting temperature, and roasting time on the quality of the final iron concentrate were discussed. Moreover, the iron phase transformation and change in magnetism of the sample were studied. The results indicated that an iron concentrate with an iron grade of 65.30% and a recovery of 85.85% could be obtained under the conditions of gas-flow rate of 8 m3/h, H₂ concentration of 50%, and fluidized magnetizing roasting at 600 ℃ for 20 s. X-ray diffraction analysis, phase analysis, and magnetism analysis on the roasted materials indicated that the hematite–limonite could be transformed into magnetite during the fluidized magnetizing roasting process, and effective separation of iron and gangues could be easily achieved by the weak magnetic separation.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Forming impulses for partial demagnetizing of rare-earth permanent magnets
Formowanie impulsów dla częściowego odmagnesowania magnesów trwałych z ziem rzadkich
Autorzy:: Makarov, D.A.
Nesterin, V.A.
Yakovlev, L.S.
Andreev, V.N.
Spiridonov, A.A.
Tematy:: magnes trwały
pierwiastki ziem rzadkich
odmagnesowanie
impuls
rare-earth permanent magnets
impuls magnetizing methods; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Elektrotechniki
Powiązania:: https://bibliotekanauki.pl/articles/159927.pdf Link otwiera się w nowym oknie
Opis:: In manufacture of facilities with permanent magnets there are some tasks when application of gauged magnitudes of magnetic characteristics of permanent magnets is required. In order to solve such tasks it is necessary to develop the methods of partial demagnetizing. Within an impulse magnetic field it is carried out at the expense of feeding series of impulses of demagnetizing field. For monitoring a level of a magnet field the carrying force P of the permanent magnet may be used. The choice of the law of impulse forming depends on the set requirements in an exactitude and productivity of the partial demagnetizing process. Process of partly demagnetizing assumes one-side approximation to a certain value of magnetization along the magnetizing curve, beginning from the maximal value, without operations of partly magnetic bias of the permanent magnet when its magnetization decreased below the given level. Comparing the different laws of forming impulses is made using mathematical modeling of the partial demagnetizing process, based on real characteristics of permanent magnets.
W wyrobie produktów z magnesami trwałymi zachodzi konieczność stosowania określonych charakterystyk magnetycznych. W tym celu konieczne jest opracowanie metod częściowego odmagnesowania przez powodowanie szeregu impulsów pola odmagnesowującego. Dla obserwowania poziomu pola magnetycznego można użyć siłę nośną P magnesu trwałego. Wybór prawa, formowanie impulsu zależy od zadanych wymagań odnośnie dokładności i skuteczności procesu odmagnesowania. Proces częściowego odmagnesowania zakłada przybliżenie pewnej wartości namagnesowania wzdłuż krzywej magnesowania zaczynając od wartości maksymalnej bez działania częściowego magnetycznego magnesowania wstępnego magnesu trwałego gdy namagnesowanie maleje poniżej danego poziomu. Porównanie różnych praw formowania impulsów wykonuje się stosując modelowanie matematyczne procesu odmagnesowania, w oparciu o rzeczywiste charakterystyki magnesów trwałych.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Magnetizing current effect minimization in current transformers
Autorzy:: Dusza, D.
Rzepecki, B.
Tematy:: current transformer
value converter
ratio
error minimization
magnetizing current effect
current transformer's error
current measurement; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/1813967.pdf Link otwiera się w nowym oknie
Opis:: Magnetizing current effect minimization in current transformers is considered in this paper. Double-core current transformer operation is described in the following text. The influence of the magnetizing current, which is a significant element of current transformer's error, has been minimized in a new type of double-core current transformer connection. The accuracy evaluation of built double-core current transformer has been carried out according to obtained transformation precision.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: The Formation, Properties and Use of Dispersed Iron-Graphite Metallurgical Waste
Autorzy:: Dan, Leonid
Maslov, Vladimir
Trofimova, Larysa
Cios, Grzegorz
Tematy:: dispersed iron-graphite waste
graphite
iron oxides
specific saturation magnetization
magnetizing annealing
carbothermal self-reduction
magnetic graphite; Pokaż więcej
Wydawca:: Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Powiązania:: https://bibliotekanauki.pl/articles/2172384.pdf Link otwiera się w nowym oknie
Opis:: Dispersed wastes containing graphite, iron, and its oxides, getting into the air and accumulating in landfills, cause serious harm to human health and the environment. Moreover, even if the issue of the localization of these wastes has been solved successfully, their disposal has not yet been fully organized. In the present study, a systematic analysis of the dispersed iron-graphite waste (IGW) conditions for the formation at metallurgical enterprises, their structure, and their properties were carried out. In this case, special attention is focused on the electrophysical properties: specific saturation magnetization and volume resistivity. The presence of magnetic properties in IGW, combined with low electrical resistivity, makes IGW a promising and inexpensive raw material for obtaining cheap composite materials with radio shielding and radio absorbing properties in the microwave range. As a result of the research, effective ways of improving the magnetic properties of IGW by high-temperature treatment were obtained. The practical result of the research was the development and implementation of a technological scheme of dispersed IGW complex processing, which makes it possible to solve a twofold task – to exclude the ingress of iron-graphite wastes into the environment and to obtain a cheap material for protection against microwave radiation.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Induction machine with pole-changing winding for turbomechanisms
Autorzy:: Bobojanov, Makhsud
Tematy:: basic scheme of winding
differential leakage factor
Görges polygone
magnetizing forces
pole-changing winding
pole amplitude modulation
winding factor; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czasopisma i Monografie PAN
Powiązania:: https://bibliotekanauki.pl/articles/24202741.pdf Link otwiera się w nowym oknie
Opis:: This paper investigates the possibilities for developing a pole-changing winding with a pole ratio of 3:4 with improved electromagnetic properties. Such a winding can be used in two-speed induction motors for turbo mechanisms. The scheme of the new winding was obtained by using a discretely-specified spatial function method developed at the Tashkent State Technical University. A comparison of the parameters obtained for a similar winding received by the pole amplitude modulation method has been presented. Design of a new motor with a new winding is developed based on the standard induction motor. The paper presents results of laboratory tests, too.
Dostawca treści:: Biblioteka Nauki

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