A Novel Technique for the Measurement of relative permeability of magnetic materials (original) (raw)
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Journal of Applied Physics, 2013
This paper describes the experimental results obtained by a broadband permeability measurement method based on the full-wave electromagnetic (EM) analysis of a non-reciprocal transmission line. The method offers a new experimental tool for measuring the broadband dynamic behavior of ferrites whatever their magnetization state. The methodology and experimental setup are presented with the aim of extracting both the permittivity and the two components (diagonal l and off-diagonal j) of the permeability tensor. Experimental data on commercial ferrites set in different magnetization states are presented and discussed. Furthermore, this method opens perspectives for the determination of other useful magnetic parameters such as resonance linewidth DH. This quantity can be then measured at different frequencies, where conventional resonant methods give a value at a fixed frequency. V C 2013 AIP Publishing LLC. [http://dx.
A new swept-frequency permeameter for measuring the complex permeability of thin magnetic films
IEEE Transactions on Magnetics, 1988
A permeameter is described which measures the complex permeability of anisotropic thin magnetic films over a continuous fre quency spectrum. The system resolves the permeability into both real and imaginary parts, or magnitude and phase. The frequency span of the permeameter, 0.1-200 MHz, is larger than that of previously re ported permeameters. The system has a measurement error of approx imately one-percent which for the samples used here corresponds to a low level permeance detection limit of about 1 I'm, an order of mag nitude below the previously reported low level limit of 13 I'm. The sys tem is both compact in size and convenient to use, with measurements taken over the whole frequency range in less than a minute. The per meameter combines hoth a new design and construction technique of the permeance measuring jig, with a new application of test equip ment. The permeance measuring jig has a coaxial structure and is built using layers of appropriately milled copper-clad microstrip. A scatter ing parameter test set, driven and controlled by a network analyzer, is used to measure the scattering parameters of the permeance mea suring jig, from which the permeance of a sample may be determined. 1979. He is also a member of the Materials Science & Engineering Faculty at Texas. His current research interests are in the ion beam processing of materials, high dose implant ation , solid phase epitaxy in semiconductors, and amorphous magnetic thin films.
Measurements of Magnetic Permeability of Soft Steel at High Frequencies
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The Fermilab Booster does not have a vacuum chamber, which would screen the beam from laminations of its dipoles cores. Therefore the Booster impedance is mainly driven by the impedance of these dipoles. Recently an analytical model of the laminated dipole impedances was developed. However, to match the impedance measurements with calculations one needs an accurate measurement of soft steel magnetic permeability. This paper presents the measurements of high frequency magnetic permeability for soft steel similar to the steel of Booster laminations. The measurements were performed in a frequency range from ~10 MHz to 1 GHz and were based on a study of electromagnetic wave propagation in 30 cm long transmission line built with help of steel strip. Measurements were performed in a DC magnetic field to observe the effect of steel saturation on the high frequency permeability. Both real and imaginary parts of the permeability were measured. As expected their values were decreasing with frequency increase from 10 MHz to 1 GHz and with saturation of steel DC permeability.
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Proc. of the 2019 International Symposium on Electromagnetic Compatibility (EMC Europe 2019), Barcelona, Spain, September 2–6, 2019., 2019
This paper describes the procedure for extracting complex permeability for inductive toroidal cores using short coaxial sample holders in the frequency range between 100 Hz and 110 MHz. Extracting complex permeability from measured input impedance is performed based on the inductive behavior of the coaxial holder. Three numerical techniques based on non-uniform transmission line theory, frequency domain finite difference method, and 3D Method of Moments (MoM) are used to verify above methodology. The obtained results are discussed in detail.
IEEE Transactions on Magnetics, 2016
The performances of electrical machines depend highly on the behavior of ferromagnetic materials. In some applications, these materials operate under DC polarization, i.e. when the magnetic field oscillates around a DC bias. In that condition, it is required to know the incremental permeability which characterizes the magnetic behavior of the material around the operating point. In this paper, a non-destructive approach, involving a combination of experiment and Finite Element (FE) technique, is presented in order to determine the incremental permeability. The proposed sensor is based on the four-needles method. With this sensor, Bowler et al. have proposed a method to determine the initial permeability of homogeneous metal plates based on an analytical model. Here we propose to use the same kind of sensor to determine the incremental permeability. The measurement process is analyzed using a FE model. It is shown that the analytical approach reaches its limits if the permeability of the plate and its thickness become too high. A combination between the measurements and a FE model is introduced to overcome this difficulty to determine the incremental permeability. The study of two magnetic steel samples illustrates the interest of this method.
Improving reliability of magnetic mutual impedance measurement at high excitation level
2011 IEEE International Instrumentation and Measurement Technology Conference, 2011
Power electronic designers are interested in characterization of the magnetic cores permeability up to 10MHz and at high induction level. To achieve this aim, different experimental setups are used to measure mutual impedance spectra. First, impedance measurement methods are carried out on toroidal wound core of 20 µm nanocrystalline ribbons. Measurement uncertainties are estimated and a confidence factor is introduced as a useful consistency test to improve measurement reliability. Then a lumped equivalent circuit is identified to model electrostatic and magnetic frequency behavior of the device under test. It allows calculating complex permeability spectra over the resonance frequency of the device under test. Finally, we point out the limitation due to high excitation level. According to that, a flux-metric experimental setup is described and elliptical hysteresis-loops are measured. These results allow to consider magnetic linear behavior until a few 10mT and to extend complex permeability calculations to high induction level with good reliability.
IEEE Transactions on Magnetics, 2002
This paper deals with the characterization of the magnetic permeability of soft magnetic materials under a rotating magnetic field. The paper reviews the principle of the rotating-flux-density device used for measurement of flux density, then describes the mathematical method used to calculate permeability from the measurements. The method combines direct and inverse solutions and is based on a functional minimization sequence. An example demonstrates the validity of the method. Finally, the paper discusses the uniqueness of the solution and its sensitivity.