The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform

Byoung-hee Lee - One of the best experts on this subject based on the ideXlab platform.

Koji Fujiwara - One of the best experts on this subject based on the ideXlab platform.

  • Single sheet tester having open Magnetic Path for measurement of magnetostriction of electrical steel sheet
    IEEE Transactions on Magnetics, 1999
    Co-Authors: T. Nakase, M. Nakano, Koji Fujiwara, N. Takahashi
    Abstract:

    A single sheet tester having closed Magnetic Path (a closed type of SST) has a problem that measurement accuracy of magnetostriction is considerably affected by electroMagnetic force between specimen and yoke. Therefore, an open type has been developed. In order to get uniform flux distribution in a sufficiently large region, a compensating magnetizing winding is installed, and a method of waveform control is investigated, in which applied voltages to main and compensating windings are adjusted individually. The effectiveness of the newly developed open type is demonstrated by measuring magnetostrictions of thin amorphous sheet as well as highly grain-oriented silicon steel sheet.

  • 3-D Magnetic Field Analysis of Epstein Frame for Measuring Magnetic Characteristics
    Electric and Magnetic Fields, 1995
    Co-Authors: T. Nakata, M. Nakano, Koji Fujiwara, N. Takahashi, H. Ohashi, H. L. Zhu
    Abstract:

    The effective Magnetic Path length L m of the Epstein frame is specified as 94cm by the IEC (International Electrotechnical Commission) standard.1 In order to measure accurately the Magnetic characteristics, L m which is a function of the flux density and quality of specimen should be determined exactly. As the Magnetic circuit of the Epstein frame is three-dimensional, 3-D numerical analysis taking account of nonlinearity is necessary.

  • Accurate measurement method of magnetization curve using ring specimen
    Journal of Magnetism and Magnetic Materials, 1992
    Co-Authors: T. Nakata, Koji Fujiwara, Norio Takahashi, Masanori Nakano, Y. Ogura
    Abstract:

    Abstract When the magnetization curve (BH) is measured in a ring specimen, the curve obtained has an intrinsic error source, because the mean Magnetic Path length is assumed to be equal to the mean geometric Path length. In this paper, a method is proposed for estimating the true BH curve by means of numerical calculations. This newly developed method enables us to eliminate the error in setting the mean Magnetic Path length.

  • An improved method for determining the DC magnetization curve using a ring specimen
    IEEE Transactions on Magnetics, 1992
    Co-Authors: T. Nakata, Koji Fujiwara, Norio Takahashi, Masanori Nakano, Y. Ogura, K. Matsubara
    Abstract:

    When the DC magnetization curve (B-H) of nonoriented material is measured in a ring specimen, there is an intrinsic error due to the assumption that the mean Magnetic Path length is equal to the mean geometric Path length. A novel method for determining the B-H curve accurately is proposed. The validity of the method is verified by experiments. >

Tsutomu Mizuno - One of the best experts on this subject based on the ideXlab platform.

  • AC Resistance Reduction of a Flexible Wireless Power Transmission Coil Using Magnetic Path Control Technology at 13.56 MHz
    IEEE Transactions on Magnetics, 2019
    Co-Authors: Yuta Tokudaiji, Daichi Miura, Yusuke Hattori, Kohei Murasato, Tsutomu Mizuno
    Abstract:

    To reduce the size and weight of wireless power transfer devices, lightweight, thin, and highly efficient power-transmitting and power-receiving coils are required. In this paper, we describe a spiral-shaped flexible flat wire coil with reduced ac resistance, which is suitable for being mounted on electric tools and smart phones. A method for reducing the ac resistance of a flexible coil for wireless power transfer at high frequencies is required. The proposed flexible coil uses Magnetic Path control technology to suppress the skin and proximity effects by applying a Magnetic material to the coils. The proposed coil reduces the ac resistance by 18% at 13.56 MHz in the ISM band, and improves the Q value of the coil by 27%. As a result, the transmission efficiency improves by 1.3% when the distance between the coils in 10 mm.

  • Copper Loss Reduction in Wireless Power Transmission Coil Using Magnetic Path Control Technology
    2018 21st International Conference on Electrical Machines and Systems (ICEMS), 2018
    Co-Authors: Shun Endo, Tsutomu Mizuno
    Abstract:

    Litz copper wires are generally used in wireless power transmission coils for electric vehicles to reduce high-frequency losses. However, the production of Litz wire is expensive. Herein, a copper plate coil is proposed, which can be manufactured at a low cost. To overcome the issues of high copper loss and low transmission efficiency, a Magnetic flux Path control technique is also proposed. Using this technology in the copper plate coil, AC resistance is decreased from 187.4 to $\mathbf{80.2\ m}\Omega$ .

N. Takahashi - One of the best experts on this subject based on the ideXlab platform.

  • Single sheet tester having open Magnetic Path for measurement of magnetostriction of electrical steel sheet
    IEEE Transactions on Magnetics, 1999
    Co-Authors: T. Nakase, M. Nakano, Koji Fujiwara, N. Takahashi
    Abstract:

    A single sheet tester having closed Magnetic Path (a closed type of SST) has a problem that measurement accuracy of magnetostriction is considerably affected by electroMagnetic force between specimen and yoke. Therefore, an open type has been developed. In order to get uniform flux distribution in a sufficiently large region, a compensating magnetizing winding is installed, and a method of waveform control is investigated, in which applied voltages to main and compensating windings are adjusted individually. The effectiveness of the newly developed open type is demonstrated by measuring magnetostrictions of thin amorphous sheet as well as highly grain-oriented silicon steel sheet.

  • 3-D Magnetic Field Analysis of Epstein Frame for Measuring Magnetic Characteristics
    Electric and Magnetic Fields, 1995
    Co-Authors: T. Nakata, M. Nakano, Koji Fujiwara, N. Takahashi, H. Ohashi, H. L. Zhu
    Abstract:

    The effective Magnetic Path length L m of the Epstein frame is specified as 94cm by the IEC (International Electrotechnical Commission) standard.1 In order to measure accurately the Magnetic characteristics, L m which is a function of the flux density and quality of specimen should be determined exactly. As the Magnetic circuit of the Epstein frame is three-dimensional, 3-D numerical analysis taking account of nonlinearity is necessary.

Andre M. S. Mendes - One of the best experts on this subject based on the ideXlab platform.

  • Improved inductance calculation in variable power inductors by adjustment of the reluctance model through Magnetic Path analysis
    2019 IEEE Energy Conversion Congress and Exposition (ECCE), 2019
    Co-Authors: Sarah Saeed, Jorge Garcia, Marina S. Perdigao, Valter S. Costa, Bruno Baptista, Andre M. S. Mendes
    Abstract:

    This paper presents a study to improve the inductance calculation of Magnetic elements for power converters, particularly important in the case of applications using variable inductors. Several factors have been taken into consideration, such as: the permeability definition under saturation, the temperature effect on the Magnetic material behavior, and the distribution of saturated regions in the Magnetic core which results in an accurate estimation of reluctance Paths. Further depth is given to the study by using Finite Element Analysis to simulate a variable inductor and analyze the effect of the latter mentioned factors. The studied analysis is then compared with experimental results to prove the validity of the proposed improvements.