Temat: demagnetization - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Development of a technique for inductive measurement of laser-induced magnetization dynamics in thin films
Autorzy:: Ilit’, Tomáš
Valko, Pavol
Držík, Milan
Ušáková, Marianna
Šoka, Martin
Marton, Marian
Behúl, Miroslav
Vojs, Marian
Tematy:: laser-induced demagnetization
pulsed inductive microwave magnetometry
ultrafast demagnetization detection; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/220843.pdf Link otwiera się w nowym oknie
Opis:: We present the development of a technique for studying laser-induced magnetization dynamics, based on inductive measurement. The technique could provide a simple tool for studying laser-induced demagnetization in thin films and associated processes, such as Gilbert damping and magnetization precession. It was successfully tested using a nanosecond laser and NiZn ferrite samples and - after further development - itis expected to be useful for observation of ultra-fast demagnetization. The combination of optical excitation and inductive measurement enables to study laser-induced magnetization dynamics in both thin and several micrometre thick films and might be the key to a new principle of ultrafast broadband UV-IR pulse detection.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 2.

Tytuł:: Analysis of Current Signals in a Partially Demagnetized Vector Controlled Interior Permanent Magnet Generator
Autorzy:: Quintal-Palomo, Roberto Eduardo
Tematy:: IPM
PMSG
co-simulation
DFOC
demagnetization; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/1193712.pdf Link otwiera się w nowym oknie
Opis:: This manuscript analyzes the operation of an interior permanent magnet (IPM) machine working as a permanent magnet synchronous generator (PMSG). The partial demagnetization operation is analyzed. To obtain more accurate voltages and currents of the machine, finite element analysis (FEA) is used in co-simulation with the full converter and the converter’s control algorithm. Direct field oriented control (DFOC) shows robustness by maintaining the speed even with a 25% demagnetized PMSG. Also, an analysis of the rotating reference frame DQ signals is done to asses demagnetization.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 3.

Tytuł:: Magnetization dependent demagnetization characteristic of rare-earth permanent magnets
Autorzy:: Bavendiek, Gregor
Müller, Fabian
Sabirov, Jamshid
Hameyer, Kay
Tematy:: demagnetization
magnetic hysteresis
magnetization processes
permanent magnets; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/140527.pdf Link otwiera się w nowym oknie
Opis:: Accurate demagnetization modelling is mandatory for a reliable design of rare- earth permanent magnet applications, such as e.g. synchronous machines. The magnetization of rare-earth permanent magnets requires high magnetizing fields. For technical reasons, it is not always possible to completely and homogeneously achieve the required field strength during a pulse magnetization, due to stray fields or eddy currents. Not sufficiently magnetized magnets lose remanence as well as coercivity and the demagnetization characteristic becomes strongly nonlinear. It is state of the art to treat demagnetization curves as linear. This paper presents an approach to model the nonlinear demagnetization in dependence on the magnetization field strength. Measurements of magnetization dependent demagnetization characteristics of rare-earth permanent magnets are compared to an analytical model description. The physical meaning of the model parameters and the influence on them by incomplete magnetization are discussed for different rare-earth permanent magnet materials. Basically, the analytic function is able to map the occurring magnetization dependent demagnetization behavior. However, if the magnetization is incomplete, the model parameters have a strong nonlinear behavior and can only be partially attributed to physical effects. As a benefit the model can represent nonlinear demagnetization using a few parameters only. The original analytical model is from literature but has been adapted for the incomplete magnetization. The discussed effect is not sufficiently accurate modelled in literature. The sparse data in literature has been supplemented with additional pulsed-field magnetometer measurements.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 4.

Tytuł:: Influence of rotor’s cage resistance on demagnetization process in the line start permanent magnet synchronous motor
Autorzy:: Zawilak, Tomasz
Tematy:: demagnetization
falling out of step
permanent magnets
synchronous motor; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/141077.pdf Link otwiera się w nowym oknie
Opis:: This paper deals with the finite element analysis of the demagnetization process of the line start permanent magnet synchronous motor. Special attention has been paid to demagnetization risk assessment after resynchronization during a short-term supply power outage. The current and torque waveforms have been determined assuming the difference depending initial rotor position angle. It has been demonstrated that the highest demagnetization risk occurs when resynchronization (motor reclosing) is performed when induced electromotive forces are in anti-phase to the supply voltage waveforms. The effect of cage winding resistance on the risk of demagnetization is examined and discussed.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 5.

Tytuł:: Performance comparison of double stator permanent magnet machines
Autorzy:: Awah, Chukwuemeka Chijioke
Tematy:: demagnetization
double stator
induced voltage
losses
power and torque; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/2172793.pdf Link otwiera się w nowym oknie
Opis:: The electromagnetic and output performance characteristics of three (3) different types of double stator permanent magnet machines are quantitatively compared and presented in this study, in order to determine the most promising machine topology amongst the considered machine types, for potential practical applications(s). Two-dimensional (2D) and three-dimensional (3D) finite element analysis (FEA) methods are deployed in the computation of the performance metrics using ANSYS-MAXWELL software. The compared machines in this work are designated as: Machine 1, Machine 2 and Machine 3, respectively. The investigated machines have varying structural arrangements and two separate excitation sources. Machine 1 has its magnets situated in the outer stator with corresponding armature windings on both inner and outer stators. The magnets of Machine 2 are located in its inner stator while it has armature windings on both inner and outer stator parts. More so, Machine 3 is equipped with magnets in its inner and outer stators, though without armature windings on the inner stator section. The considered performance metrics include: inducedelectromotive force (induced-EMF), torque, power, demagnetization, losses and efficiency. The results show that the investigated Machine 3 has higher induced-EMF value and more sinusoidal electromotive force waveform than the other compared machines. Consequently, Machine 3 also has larger electromagnetic torque and power. Moreover, Machine 1 has the best flux-weakening potential, obtained from both the ratio of its maximum speed to base speed and the flux-weakening factor ( kp).
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 6.

Tytuł:: Measures to reduce the residual field and field gradient inside a magnetically shielded room by a factor of more than 10
Autorzy:: Voigt, J.
Knappe-Grüneberg, S.
Schnabel, A.
Körber, R.
Burghoff, M.
Tematy:: magnetic shielding
magnetic shielded room
msr
residual field
residual field gradient
degaussing
demagnetization; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/220358.pdf Link otwiera się w nowym oknie
Opis:: Very low residual magnetic field and field gradients are essential for a number of high resolution fundamental physical experiments and for further improvement of very sensitive magnetic measurement devices. The scope ranges from spin precession experiments, e.g. with ³He or neutrons, to biomagnetic measurements, like magnetoencephalograms, and to low field MR spectroscopy. One method of reducing environmental magnetic noise is to use a magnetically shielded room (MSR). Here, measures are demonstrated to improve residual field and field gradient inside a common MSR by a factor of more than 10 by a specific degaussing procedure, material selection of prefabricated parts and active shielding. The process is independent of the shielding factor and works also properly for heavily shielded rooms.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 7.

Tytuł:: Sensitivity Limits and Functional Characteristics of Fluxgate Sensors with Rod-Shaped Magnetic Cores
Granice czułości i charakterystyki funkcjonalne czujników fluxgate z rdzeniami magnetycznymi w kształcie prętów
Autorzy:: Kopala, Dominika
Ostaszewska-Liżewska, Anna
Szewczyk, Roman
Tematy:: fluxgate sensors
demagnetization coefficient
magnetic permeability
czujniki fluxgate
współczynnik demagnetyzacji
przenikalność magnetyczna; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Powiązania:: https://bibliotekanauki.pl/articles/2090887.pdf Link otwiera się w nowym oknie
Opis:: Highly sensitive fluxgate magnetic field sensors with rod-shaped cores are widely used for non-destructive testing as well as for industrial applications. However, in case of both Foerster and Vacquier (two-core sensors configurations), fluxgate sensors sensitivity is directly connected with the relative magnetic permeability of the sensor’s core. It should be highlighted that the magnetic permeability of rod-shaped magnetic cores is driven mainly by the demagnetization factor determined by its slenderness (aspect ratio). The paper presents the analyses of sensitivity limits of fluxgate sensors with rod-shaped cores. On the base of estimations of demagnetization factor specific for fluxgate sensors, it is shown that in case of rod-shaped cores, the sensor’s sensitivity is connected with the shape of the core rather than its relative magnetic permeability. This conclusion is essential during the development and optimization of functional characteristics of fluxgate sensors.
Bardzo czułe sensory pola magnetycznego typu fluxgate z rdzeniami w kształcie prętów są szeroko stosowane w badaniach nieniszczących, jak również w zastosowaniach przemysłowych. Jednak zarówno w przypadku czujnika w konfiguracji Foerster’a, jak i Vacquier’a (obie konfiguracje dotyczą sensorów dwurdzeniowych) ich czułość jest bezpośrednio związana ze względną przenikalnością magnetyczną rdzeni. Należy podkreślić, że o przenikalności magnetycznej prętowych rdzeni magnetycznych decyduje przede wszystkim współczynnik rozmagnesowania określony przez jego smukłość (proporcje). W artykule przedstawiono analizę granic czułości sensorów typu fluxgate z rdzeniami prętowymi. Na podstawie oszacowań współczynnika rozmagnesowania charakterystycznego dla czujników typu fluxgate wykazano, że w przypadku rdzeni prętowych czułość sensora związana jest raczej z kształtem rdzenia niż z jego względną przenikalnością magnetyczną. Wniosek ten jest szczególnie ważny podczas opracowywania i optymalizacji charakterystyk funkcjonalnych czujników fluxgate.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 8.

Tytuł:: Introduction to the Special Section on Intelligent Fault Monitoring and Fault–Tolerant Control in Power Electronics, Drives and Renewable Energy Systems
Autorzy:: Malinowski, Mariusz
Levi, Emil
Orlowska-Kowalska, Teresa
Tematy:: electrical drives
permanent magnet machine
induction motors
sensor fault
winding fault
demagnetization fault
neural networks
observers; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/1193706.pdf Link otwiera się w nowym oknie
Opis:: This article constitutes an introductory part of the special section on Intelligent Fault Monitoring and Fault-Tolerant Control in Power Electronics, Drives and Renewable Energy Systems. In the current issue of the journal, the first part of this section is published. Accepted articles are focussed mainly on the sensor-fault diagnosis methods for T-type inverter-fed dual- three phase PMSM drives, partial demagnetization, faults of the permanent magnet synchronous generator (PMSG) and online open phase fault detection (FD) in the sensorless five-phase induction motor drive implemented with an inverter output LC filter and third harmonic injection. Also, neural networks (NN) application in the detection of stator and rotor electrical faults of induction motors has been proposed in one of the papers, and the observer-based FD concept for unknown systems using input–output measurements was applied to a brushless direct current motor drive with unknown parameters.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 9.

Tytuł:: Optimized design of a high-power-density PM-assisted synchronous reluctance machine with ferrite magnets for electric vehicles
Autorzy:: Liu, X.
Li, Y.
Liu, Z.
Ling, T.
Luo, Z.
Tematy:: permanent magnet (PM)-assisted synchronous reluctance machine
ferrite magnet
demagnetization
mechanical strength
torque ripple
finite element analysis; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/140849.pdf Link otwiera się w nowym oknie
Opis:: This paper proposes a permanent magnet (PM)-assisted synchronous reluctance machine (PMASynRM) using ferrite magnets with the same power density as rareearth PM synchronous motors employed in Toyota Prius 2010. A suitable rotor structure for high torque density and high power density is discussed with respect to the demagnetization of ferrite magnets, mechanical strength and torque ripple. Some electromagnetic characteristics including torque, output power, loss and efficiency are calculated by 2-D finite element analysis (FEA). The analysis results show that a high power density and high efficiency of PMASynRM are obtained by using ferrite magnets.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 10.

Tytuł:: Masking of ferromagnetic ellipsoidal shell in Earth’s magnetic field
Autorzy:: Jakubiuk, K.
Wołoszyn, M.
Zimny, P.
Tematy:: mathematical models of magnetic field
magnetization of ferromagnetic object
masking of ferromagnetic object
windings for demagnetization of the ship; Pokaż więcej
Wydawca:: Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Powiązania:: https://bibliotekanauki.pl/articles/97594.pdf Link otwiera się w nowym oknie
Opis:: A ferromagnetic object, located in the Earth’s magnetic field, changes the distribution of that field. By measuring such disturbances it is possible to detect the object and destroy it. To conceal the object, a special winding is placed inside its ferromagnetic shell, which function is to eliminate the disturbances in the distribution of the Earth’s magnetic field. A thin walled ellipsoidal shell made of ferromagnetic material are examined as the object model. Coils are placed inside the shell and their function is to generate a magnetic field, which eliminates the effect the shell makes on the distribution of the Earth’s magnetic field in the surrounding area. Such a procedure is called magnetic masking and the winding used for this purpose is called the masking winding. The possibility of building the masking windings for the ferromagnetic ellipsoidal shell, situated in a magnetic field transverse in relation to its major axis, is also examined. Masking of a thin-walled ellipsoidal ferromagnetic object located in the longitudinal magnetic field is described in the article [1]. Investigating the possibility of masking of objects in a transverse magnetic field presented in this article will allow for a comprehensive assessment of a possibility of masking thin walled ferromagnetic objects of elongated ellipsoidal shape. The solution of Maxwell’s equations, which describe the magnetic field distribution caused by the ferromagnetic shell presence in the Earth’s magnetic field, are applied. Furthermore, the ability of selecting coils, which fully eliminate the perturbations of the magnetic field outside the shell are proven.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Informacja

Wyszukujesz frazę "demagnetization" wg kryterium: Temat