Study on Magnetic Properties of Magnetic Materials Using Improved Hybrid Vector Hysteresis Model
Dandan Li^{1}, Zhenyang Qiao^{1}, Na Yang^{1}, Yinmao Song^{1}, Yongjian Li^{2}
^{1}School of Building Environment Engineering, Zhengzhou University of Light Industry, Zhengzhou, Henan, CHINA; ^{2}State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin, CHINA
This paper presents an improved 2D vector hybrid hysteresis model to study the vector magnetic properties of magnetic materials under alternated and rotational magnetic field. Combining Preisach model and StonerWohlfarth (SW) model, the vector hybrid hysteresis model was established for magnetic materials in previous paper. The model is improved in this paper through adjusting the parameters to solve the question that simulation curve was not closed. The alternated and rotational hysteresis properties are calculated under different excitation frequency, respectively. It is shown that the simulation curve of improved vector model were closed and can well agree with the experimental measurement ones.
Application of Hamilton's Principle to the Electromagnetic Potential in Spacetime with Bounded Polarizable Regions
Terje Graham Vold
Continuum Technology, Inc., United States of America
The principle of stationary action is applied to the electromagnetic fourvector potential in spacetime made up of volumes, each containing a uniformly polarizable medium, separated by boundaries across which the potential, but not generally its derivative, is continuous. This leads to a simple system of equations for coefficients of an expansion in basis functions of the potential at boundary points, which may be viewed as Galerkin's method applied to the single fourvector spacetime equation expressing Maxwell's inhomogeneous scalar and threevector equations in space and time written in terms of the scalar and vector potentials. Application to linearly polarizable media allows a boundary element method applicable to volumes with boundaries of any shape; application to nonlinear media allows a finite element method. Computational time is similar to other methods, but advantages include simpler algebra and structure, no spurious solutions, and no limits on frequency from zero to wave velocity over boundary mesh cell length, or on polarizability including complex electrical polarizability representing conductivities of good insulators, good conductors, and intermediate cases in the same problem. Theoretical details and numerical results of computational examples are given.
Computation of Eigenvalues and Eigenfunctions in the Solution of Eddy Current Problems with Modal Methods
Theodoros Theodoulidis^{1}, Anastassios Skarlatos^{2}
^{1}University of Western Macedonia, Greece; ^{2}CEA Saclay, France
For eddy current problems in bounded domains, an important aspect of the solution of the corresponding differential equation, is the accurate computation of the discrete eigenvalues and their corresponding eigenfunctions. For conductive media these eigenvalues are generally complex and in canonical geometries they are computed as roots of expressions involving trigonometric or Bessel functions. Until now, location and computation of these roots included complex plane search methods involving NewtonRaphson iterations or a Cauchy integral approach. In this paper, we follow an alternative path by treating the differential equation that describes the electromagnetic field as a general SturmLiouville problem. We then apply a global function method to transform the problem into a matrix eigenvalues problem. Although this approach is frequently used in high frequency studies involving wave propagation, it is applied for the first time to low frequency diffusive field configurations such as the eddy current ones.
TimeDomain Homogenization of Foil Windings in 2D Magnetodynamic FiniteElement Models
Carlos A. Valdivieso^{1,2,4}, Brahim Ramdane^{1}, Gerard Meunier^{1}, Ruth V. Sabariego^{2}, Johan Gyselinck^{3}, Christophe Guerin^{4}
^{1}Univ. Grenoble Alpes, CNRS, Grenoble INP, G2Elab, F38000 Grenoble, France; ^{2}KU Leuven, Dept. Electrical Engineering, EnergyVille, 3000 Leuven, Belgium; ^{3}Université libre de Bruxelles, BEAMS department, 1050 Brussels, Belgium; ^{4}Altair Engineering France, 38240 Meylan, France
In this paper, an approach for the timedomain homogenization of foil windings in twodimensional (2D) finiteelement (FE) models is presented. The homogenized formulation is characterized by an axial current redistribution and a radial interturn voltage gradient. The method is successfully applied to an axisymmetric 18turn foilwinding inductor. The local and global results agree very well with those obtained by an accurate but expensive FE model in which all turns are explicitly discretized.
A Method for the Definition of Hysteresis Operator in Three Dimensional Case
Dandan Li^{1}, Zhenyang Qiao^{1}, Na Yang^{1}, Yinmao Song^{1}, Yongjian Li^{2}
^{1}School of Building Environment Engineering, Zhengzhou University of Light Industry, Zhengzhou, Henan, CHINA; ^{2}State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin, CHINA
This paper presents a method for the definition of hysteresis operator in 3D case based on the definition method of 2D hysteresis operator. According to the principle of minimum energy of magnetized steady state, the 3D hysteresis operator is established for anisotropic and isotropic materials in spherical coordinate system. The magnetization process of the hysteresis operator is studied when alternated and rotational magnetic field are applied. The properties of the hysteresis operator defined in this paper are analyzed from different perspectives. The definition of hysteresis operator lays a foundation for the establishment of 3D hybrid vector hysteresis model.
Matrix Based Rational Interpolation for New Coupling Scheme Between MHD and Eddy Current Numerical Models
Matteo Bonotto^{1,2}, Fabio Villone^{3}, Yueqiang Liu^{4}, Paolo Bettini^{1,5}
^{1}Consorzio RFX, 35127 Padova, Italy; ^{2}University of Padova, Centro Ricerche Fusione, 35131 Padova, Italy; ^{3}Consorzio CREATE, DIETI, University of Naples Federico II, Napoli, Italy; ^{4}General Atomics, San Diego, California, United States; ^{5}Department of Industrial Engineering, University of Padova, 35131 Padova, Italy
In this paper, we present a new selfconsistent coupling scheme between linear MHD model and eddy current equations, numerically
solved with a 3D integral formulation. The new strategy, based on matrixvalued rational interpolation, is able to model frequency
dependent plasma response, and takes into account plasma inertia: therefore it is valid for model both Resistive Wall Modes (RWMs)
and ideal kinks. Moreover, also toroidal flow and kinetic damping physic can be modelled.
Characteristics of 3D Magnetic Field of Square and DoubleD Coils Geometry for Wireless Power Transmission System
Lili Wang^{1,2}, Xian Zhang^{3}, Hui Xia^{1}, Zhaohui Wang^{3}, Guoqiang Liu^{1}
^{1}Institute of Electrical Engineering,Chinese Academy of Sciences, China, People's Republic of; ^{2}University of Chinese Academy of Science, Beijing, China; ^{3}Tianjin Polytechnic University, Tianjin, China
Magnetic field coupling is the key to the wireless power transmission. In this paper, we study the spatial magnetic field distribution of the two coils geometry Square Coils and DoubleD coils, which are the most commonly used in wireless charging systems. In the simulation calculation, the mathematical expression of the magnetic flux density of the Square Coils and DoubleD Coils is derived instead of using finite element simulation software. In the experiment, we built a threedimensional magnetic field measurement platform of the wireless energy transmission system to obtain the magnetic field distribution. By comparing the magnetic flux density between square coils and DoubleD coils in stimulation and experiment, we find the DoubleD coils analytical results are in good agreement with the experimental results, Moreover, the range of uniform magnetic field is generated by DoubleD coils is twice that of the SingleD coupling coils. The theoretical values of SingleD differ from the actual measured value by nearly 1/3. It shows that the DoubleD coils geometry can help strength the ability of the coupling between the coils and reduces the attenuation of the magnetic induction density during transmission. Through the study of the spatial magnetic field distribution between the two coupling mechanisms, it provides a basis for the optimization of the coupling geometry of the wireless charging system.
Magnetic Forces Behind Hyperelastic Behavior of Magnetorheological Elastomers
Ondrej Sodomka, Vojtech Skrivan, Frantisek Mach
University of West Bohemia, Faculty of Electrical Engineering, Czech Republic
A magnetic and nonlinear structural mechanic coupled problem is discussed concerning behavior of an magnetorheological elastomer. Material properties and hyperelastic character of the material were found by measurements. Based on the measurements and computations, a coupled mathematical model is proposed involving the Yeoh hyperelastic model.
Finite Element Modeling of Thin Conductors in FrequencyDomain
Jonathan Velasco^{1}, François Henrotte^{1,2}, Christophe Geuzaine^{1}
^{1}Université de Liège, Belgium; ^{2}Université Catholique de Louvain
This paper describes the development of an impedance condition for the modeling of thin round wires in a finiteelement framework. This approach exploits the use of the H(curl}; \Omega) function space, in addition to cylindrical symmetry, enabling the treatment of edges in a finite element mesh to be modeled as thin conductors. The procedure proposed solves the fullwave Maxwell problem under sinusoidal excitation (i.e. timeharmonic) using the magnetic vector potential (av) formulation.
Time Domain Analysis of Homogenized Finite Element Method for Eddy Current Analysis with Reduced Unknown Variables
Shingo Hiruma, Hajime Igarashi
Hokkaido university, Japan
This paper presents a new time domain analysis of a homogenized finite element (FE) equation. In the proposed method, the complex permeability is expressed by the continued fraction for the timedomain analysis. The unknowns relevant to the circuit equation are eliminated using the finite difference method. The resultant homogenized FE equation for reduced unknows can be effectively solved.
Using a Magnetic Charge Fourier Series to Studying the Force Density of Magnetic Lead Screws
Jonathan Bird, Mojtaba Bahrami Kouhshahi
Portland State University, United States of America
A 3D magnetic charge analytic based field analysis approach is presented that models an array of magnets by using a magnetic vector Fourier series representation. Using a Fourier series function enables the magnets relative permeability to be accounted for and also reduces the computational burden. The accuracy of the presented modelling approach is validated by studying the fields and forces created by a magnetic lead screw. The presented analytic based approach enables fundamental force density sizing relationships to be
determined.
Fast iterative schemes for the solution of eddy current problems featuring multiple conductors by integral formulations
Mauro Passarotto^{1}, Ruben Specogna^{1}, Christophe Geuzaine^{2}
^{1}Polytechnic Department of Engineering and Architecture, University of Udine, Italy; ^{2}Institut Montefiore, Université de Liège, Belgium
In recent years there has been a revival in the use of integral formulations for the numerical solution of electromagnetic problems. These formulations lead to full matrices whose computation and storage represent their bottleneck, thus, for this reason, efficient lowrank approximation techniques have been introduced to alleviate the issue. To tackle the same problem, in this paper, we propose a novel and efficient way to iteratively solve an eddy current problem using a boundary integral formulation by taking advantage of the domain splitting into disjoint conductors. Once the domain is subdivided into smaller subdomains, Krylov subspace techniques are applied to reduce the iteration time and improve the convergence performance.
Study on the Offline Interturn Fault Diagnosis Performance According to the Parameter of Interior Permanent Magnet Synchronous Machine
Hyunwoo Kim^{1}, SeungTaek Oh^{1}, HyungWoo Lee^{2}, Jongsuk Lim^{1}, Yeji Park^{1}, Ju Lee^{1}, SeungHeon Lee^{1}
^{1}Hanyang University, Korea, Republic of (South Korea); ^{2}Korea National University of Transportation, Korea, Republic of (South Korea)
This paper analyze the performance of an interturn fault diagnosis according the parameter of interior permanent magnet synchronous motor (IPMSM). If the interturn fault occurs in IPMSM, the daxis current is different from the daxis current in the healthy condition. Through the difference between the daxis current in the healthy and faulty condition, the interturn fault can be detected. Consequently, the magnitude of the daxis current determines the performance of the interturn fault diagnosis. The offline diagnosis is performed by injecting a highfrequency voltage into the IPMSM. The performance of the offline diagnosis depends on the parameter of the IPMSM. Thus, the performance of the offline diagnosis is analyzed according parameter of the IPMSM that is fault resistance, winding resistance and saliency ratio. In addition, to verify analytical method, interturn fault diagnosis is performed by coanalysis that is the link between the finite element analysis (FEA) and the control simulation tool.
