IEEJ Transactions on Power and Energy
Online ISSN : 1348-8147
Print ISSN : 0385-4213
ISSN-L : 0385-4213
Volume 137 , Issue 3
Showing 1-31 articles out of 31 articles from the selected issue
Special Issue on Electromagnetic Field Analysis of Electric Power Apparatus
Preface
Special Issue Review
Special Issue Paper
  • Yuji Shindo, Akihisa Kameari, Tetsuji Matsuo
    2017 Volume 137 Issue 3 Pages 162-172
    Published: March 01, 2017
    Released: March 01, 2017
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    Cauer realizations of the complex permeability of magnetic sheets can provide powerful means for the homogenization methods applied to the laminated magnetic sheets. The derivations of Cauer realizations are based on the recurrence formula of Bessel functions because the formula provides continued-fraction expansion of complex permeability, which corresponds to Cauer I realization. However, the physical meaning of Cauer I realization is not clearly understood, whereas Cauer II realization is interpreted as the direct discretization of magnetic materials. This paper reveals that the Cauer I realization is also derived by the polynomial expansions of eddy current fields in the magnetic sheets. Through this technique, the physical meaning of Cauer I realization is clarified. The proposed method is combined with the play model, the modeling method for the nonlinear and hysteresis properties of magnetic sheets. Simulations are performed and compared with the experimental results and finite element analysis.

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  • Kenta Mitsufuji, Masahito Nambu, Katsuhiro Hirata, Fumikazu Miyasaka
    2017 Volume 137 Issue 3 Pages 173-178
    Published: March 01, 2017
    Released: March 01, 2017
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    The Magneto Hydro Dynamics includes the complex phenomena which are interaction between the fluid motion and a magnetic field. In this study, a numerical analysis technique employing magnetic moment method and particle method has been proposed. Furthermore, the ferrofluid motion has been simulated by the proposed method. However, the ferrofluid must be modeled as multiphase flow for simulating the spiking phenomenon. In this report, the behavior of ferromagnetic powders under a magnetic field is simulated with the discrete element method and the magnetic moment method.

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  • Hiroshi Kanayama, Masao Ogino, Shin-ichiro Sugimoto, Kaworu Yodo, Hong ...
    2017 Volume 137 Issue 3 Pages 179-185
    Published: March 01, 2017
    Released: March 01, 2017
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    An iterative domain decomposition method is proposed for numerical analysis of 3-Dimensional (3D) linear magnetostatic problems taking the magnetic vector potential as an unknown function. The iterative domain decomposition method is combined with the Preconditioned Conjugate Gradient (PCG) procedure and the Hierarchical Domain Decomposition Method (HDDM) which is adopted in parallel computing. Our previously employed preconditioner was the Neumann-Neumann (NN) preconditioner. Numerical results showed that the method was only effective for smaller problems. In this paper, we consider its improvement with the Balancing Domain Decomposition DIAGonal scaling (BDD-DIAG) preconditioner. Specially, the coarse matrix solver is changed to an iterative solver for the first time.

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  • Mitsuo Hano, Keisuke Iwasaki, Ryuki Furuta, Masashi Hotta
    2017 Volume 137 Issue 3 Pages 186-194
    Published: March 01, 2017
    Released: March 01, 2017
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    Spurious-free shape functions of triangular and rectangular elements are described in this paper. Complete-type and incomplete-type shape functions of the triangular elements are discussed, and a series of shape functions including Lagrange-type and Serendipity-type functions of the rectangular elements are discussed, too. Unknowns which are incidental to the shape functions are classified according to nodes, edges, and face of the triangular or rectangular element. Intelligent elements are constructed by the nodes, edges, and face whose degrees are different. Spurious-free elements are proposed by establishment of degrees in nodes, edges, and face. Physical eigen values of resonant frequency in a waveguide are calculated by using the suprious-free finite element.

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  • Shin-ichiro Sugimoto, Masao Ogino, Hiroshi Kanayama
    2017 Volume 137 Issue 3 Pages 195-201
    Published: March 01, 2017
    Released: March 01, 2017
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    This paper deals with a 3D non-steady eddy current analysis of the rotating machine by the hierarchical domain decomposition method (HDDM). It is difficult to perform the parallel computing including the moving body without lowering the parallel efficiency. For example, the parallel computing of the rotating body by the parallel iterative method has been tried. However, its parallel efficiency is very low at approximately 60%. In this paper, in order to perform parallel computing including the moving bodies without lowering the parallel efficiency, the new algorithm is introduced to the HDDM. As a result, good scalability has been obtained by strong scaling of the rotating machine. Its parallel efficiency has been 93.3% with 96 nodes (1,536 cores) of Oakleaf-FX.

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  • Yuki Sato, Hajime Igarashi
    2017 Volume 137 Issue 3 Pages 202-207
    Published: March 01, 2017
    Released: March 01, 2017
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    This paper introduces a fast time-periodic eddy current analysis using model order reduction (MOR) and time-periodic explicit error correction (TP-EEC) method. In this method, the size of the original system is reduced by MOR and simultaneously, the convergence to steady states is accelerated by TP-EEC. It is shown that the speedup ratio of the present method compared with the conventional FEM is more than 30 for a nonlinear test problem.

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  • Yuki Hidaka, Hajime Igarashi
    2017 Volume 137 Issue 3 Pages 208-215
    Published: March 01, 2017
    Released: March 01, 2017
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    This paper presents topology optimization of rotating machines using the On-Off method with variable design region. The flux barrier shape is optimized by the present method in which the thin design regions covering the boundary of the flux barriers are adaptively modified during the optimization process. Because the design region is strongly restricted, the optimized flux barrier boundaries are expected to be rather smooth even if the smoothing procedure is not employed. Moreover the present method is based on the evolutionary algorithm which has powerful searching abilities. In order to validate its effectiveness, the flux barrier shapes of the interior permanent magnetic motors and synchronous reluctance motors are optimized by the present method. The performance of the present method is shown to be superior over that of the Rosen-brock method.

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  • Junji Kitao, Yasuhito Takahashi, Koji Fujiwara, Akira Ahagon, Tetsuji ...
    2017 Volume 137 Issue 3 Pages 216-222
    Published: March 01, 2017
    Released: March 01, 2017
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    In order to accurately represent a rotational hysteresis loss of magnetic materials, this paper proposes a novel identification method for an isotropic vector play model. The slope of shape functions for an isotropic vector play model is assumed to be an exponential function. Numerical results of alternating and rotational hysteresis losses are investigated to demonstrate the effectiveness of the proposed identification method.

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  • Shogo Fujita, Hajime Igarashi
    2017 Volume 137 Issue 3 Pages 223-229
    Published: March 01, 2017
    Released: March 01, 2017
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    Magnetoplated wires (MPW) are effective to reduce eddy current losses in power devices such as converters and contactless power transfer systems. In the convenient finite element (FE) analysis of MPW, elements must be sufficiently smaller than the skin depth. This results in large number of unknowns. This paper proposes a homogenization method using complex permeability for FE analysis of MP-coils so as to circumvent this problem. The coil impedances obtained by the proposed method with coarse elements are shown to agree well with those computed in the conventional FE analysis with fine elements.

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  • Yasuhito Takahashi, Junji Kitao, Koji Fujiwara, Takeshi Iwashita, Hiro ...
    2017 Volume 137 Issue 3 Pages 230-237
    Published: March 01, 2017
    Released: March 01, 2017
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    This paper proposes the time domain parallel finite-element method (TDPFEM) coupling with equation of motion to efficiently obtain transient solutions of electric machines using parallel computing. The proposed TDPFEM is based on an iterative procedure combined with the Newton-Raphson iteration for a nonlinear magnetic field problem and equation of motion for a rotor. The scalability of the proposed method is examined in the starting transient analysis of a cage induction motor on large-scale parallel computing environment.

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  • Yasuhito Takahashi, Takeshi Mifune, Koji Fujiwara
    2017 Volume 137 Issue 3 Pages 238-244
    Published: March 01, 2017
    Released: March 01, 2017
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    This paper investigates an approach for applying the Newton-Raphson (NR) method to time-harmonic eddy-current analyses considering nonlinear magnetization property. We derived a new formulation based on the magnetic reluctivity depending on the magnitude of a flux density vector in nonlinear time-harmonic eddy-current problems in our previous paper. In this paper, we newly present two formulations based on the maximum of locus of a flux density vector and the magnitude of imaginary or real components of a flux density vector. A magnetic field analysis of a cage induction motor with closed rotor slots is carried out and the advantages and disadvantages of the above three formulations are discussed.

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  • Hidenori Sasaki, Hajime Igarashi
    2017 Volume 137 Issue 3 Pages 245-253
    Published: March 01, 2017
    Released: March 01, 2017
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    This paper proposes a topology optimization method for rotating machines, in which the rotor shape is represented in terms of the Fourier series. The rotor shape of an IPM motor is optimized to maximize the average torque and minimize radial torque variations using the present method. The proposed method is shown to provide the optimized rotors whose performances are comparable with those obtained by the NGnet-based method. The topology optimization performed by both methods can give useful information on the motor design.

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  • Satoshi Doi, Tetsuya Aoki, Keiichi Okazaki, Yasuhito Takahashi, Koji F ...
    2017 Volume 137 Issue 3 Pages 254-260
    Published: March 01, 2017
    Released: March 01, 2017
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    Mass productions of the motor core such as the blanking of the electromagnetic steel sheet and the shrink fit cause the residual strain in the material, processing strain, which prevents the movement of magnetic walls and increases the magnetic loss in the motor. Conventionally, the increase of the magnetic loss by the processing stress was evaluated with trial products, because it couldn't be done in the design phase. So, it was difficult to optimize the motor design considering the processing stress. Therefore, this paper studies the computing method of the magnetic loss considering the blanking press strain which is particularly estimated to be large influence on the magnetic loss as follows:

    1: The magnetic flux density of each part in the motor is calculated by the two-dimensional static electromagnetic field analysis with the initial magnetization curve according to the distribution of the blanking press strain.

    2: The magnetic loss is calculated by the one-dimensional dynamic electromagnetic field analysis with the hysteresis curve according to the blanking press strain and the boundary condition based on the two- dimensional magnetic flux density.

    We think that it is effective in computing magnetic loss considering stress by blanking, because result of this approach agrees well with experimental trend.

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