A MSFEM to simulate the eddy current problem in laminated iron cores in 3D

2019 ◽  
Vol 38 (5) ◽  
pp. 1667-1682 ◽  
Author(s):  
Karl Hollaus
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Eddy Current ◽  
Eddy Currents ◽  
Three Dimensional ◽  
Harmonic Balance Method ◽  
Three Dimensions ◽  
Magnetic Vector Potential ◽  
Content Type ◽  
Element Method

Purpose The simulation of eddy currents in laminated iron cores by the finite element method (FEM) is of great interest in the design of electrical devices. Modeling each laminate by finite elements leads to extremely large nonlinear systems of equations impossible to solve with present computer resources reasonably. The purpose of this study is to show that the multiscale finite element method (MSFEM) overcomes this difficulty. Design/methodology/approach A new MSFEM approach for eddy currents of laminated nonlinear iron cores in three dimensions based on the magnetic vector potential is presented. How to construct the MSFEM approach in principal is shown. The MSFEM with the Biot–Savart field in the frequency domain, a higher-order approach, the time stepping method and with the harmonic balance method are introduced and studied. Findings Various simulations demonstrate the feasibility, efficiency and versatility of the new MSFEM. Originality/value The novel MSFEM solves true three-dimensional eddy current problems in laminated iron cores taking into account of the edge effect.

scholarly journals 3D harmonic modeling of eddy currents in segmented conducting structures

2019 ◽  
Vol 38 (1) ◽  
pp. 2-23 ◽  
Author(s):  
C.H.H.M. Custers ◽  
J.W. Jansen ◽  
M.C. van Beurden ◽  
E.A. Lomonova
Keyword(s):  
Finite Element ◽  
Eddy Current ◽  
Eddy Currents ◽  
Three Dimensional ◽  
Spatial Period ◽  
Content Type ◽  
Current Distributions ◽  
Wide Range ◽  
Conductivity Function ◽  
Electromagnetic Quantities

PurposeThe purpose of this paper is to describe a semi-analytical modeling technique to predict eddy currents in three-dimensional (3D) conducting structures with finite dimensions. Using the developed method, power losses and parasitic forces that result from eddy current distributions can be computed.Design/methodology/approachIn conducting regions, the Fourier-based solutions are developed to include a spatially dependent conductivity in the expressions of electromagnetic quantities. To validate the method, it is applied to an electromagnetic configuration and the results are compared to finite element results.FindingsThe method shows good agreement with the finite element method for a large range of frequencies. The convergence of the presented model is analyzed.Research limitations/implicationsBecause of the Fourier series basis of the solution, the results depend on the considered number of harmonics. When conducting structures are small with respect to the spatial period, the number of harmonics has to be relatively large.Practical implicationsBecause of the general form of the solutions, the technique can be applied to a wide range of electromagnetic configurations to predict, e.g. eddy current losses in magnets or wireless energy transfer systems. By adaptation of the conductivity function in conducting regions, eddy current distributions in structures containing holes or slit patterns can be obtained.Originality/valueWith the presented technique, eddy currents in conducting structures of finite dimensions can be modeled. The semi-analytical model is for a relatively low number of harmonics computationally faster than 3D finite element methods. The method has been validated and shown to be computationally accurate.

scholarly journals A mixed multiscale FEM for the eddy current problem with T,Φ-Φ and vector hysteresis

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Valentin Hanser ◽  
Markus Schöbinger ◽  
Karl Hollaus
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Eddy Current ◽  
Current Problem ◽  
Great Success ◽  
Content Type ◽  
Multiscale Finite Element Method ◽  
Multiscale Finite Element ◽  
Eddy Current Problem ◽  
Element Method

Purpose This work introduces an efficient and accurate technique to solve the eddy current problem in laminated iron cores considering vector hysteresis. Design/methodology/approach The mixed multiscale finite element method based on the based on the T,Φ-Φ formulation, with the current vector potential T and the magnetic scalar potential Φ allows the laminated core to be modelled as a single homogeneous block. This means that the individual sheets do not have to be resolved, which saves a lot of computing time and reduces the demands on the computer system enormously. Findings As a representative numerical example, a single-phase transformer with 4, 20 and 184 sheets is simulated with great success. The eddy current losses of the simulation using the standard finite element method and the simulation using the mixed multiscale finite element method agree very well and the required simulation time is tremendously reduced. Originality/value The vector Preisach model is used to account for vector hysteresis and is integrated into the mixed multiscale finite element method for the first time.

Coupling of finite element method and integral formulation for vector Helmholtz equation

2018 ◽  
Vol 37 (4) ◽  
pp. 1405-1417
Author(s):  
Sebastian Grabmaier ◽  
Matthias Jüttner ◽  
Wolfgang Rucker
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Helmholtz Equation ◽  
Three Dimensional ◽  
Boundary Integral ◽  
Integral Formulation ◽  
The Finite Element Method ◽  
Content Type ◽  
Wide Range ◽  
Element Method

Purpose Considering the vector Helmholtz equation in three dimensions, this paper aims to present a novel approach for coupling the finite element method and a boundary integral formulation. It is demonstrated that the method is well-suited for many realistic three-dimensional problems in high-frequency engineering. Design/methodology/approach The formulation is based on partial solutions fulfilling the global boundary conditions and the iterative interaction between them. In comparison to other coupling formulation, this approach avoids the typical singularity in the integral kernels. The approach applies ideas from domain decomposition techniques and is implemented for a parallel calculation. Findings Using confirming elements for the trace space and default techniques to realize the infinite domain, no additional loss in accuracy is introduced compared to a monolithic finite element method approach. Furthermore, the degree of coupling between the finite element method and the integral formulation is reduced. The accuracy and convergence rate are demonstrated on a three-dimensional antenna model. Research limitations/implications This approach introduces additional degrees of freedom compared to the classical coupling approach. The benefit is a noticeable reduction in the number of iterations when the arising linear equation systems are solved separately. Practical implications This paper focuses on multiple heterogeneous objects surrounded by a homogeneous medium. Hence, the method is suited for a wide range of applications. Originality/value The novelty of the paper is the proposed formulation for the coupling of both methods.

Calculation of eddy current losses using the electrodynamic similarity laws

2014 ◽  
Vol 63 (1) ◽  
pp. 107-114
Author(s):  
Dariusz Koteras
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Eddy Current ◽  
Eddy Currents ◽  
Numerical Calculations ◽  
Eddy Current Losses ◽  
Similarity Laws ◽  
Good Agreement ◽  
Element Method

Abstract The results of the eddy currents losses calculations with using electrodynamics scaling were presented in this paper. Scaling rules were used for obtain the values of the eddy currents losses. For the calculations Finite Element Method was used. Numerical calculations were verified by measurements and a good agreement was obtained

Analysis of spherical shell structure based on SBFEM

2020 ◽  
Vol 37 (6) ◽  
pp. 2035-2050
Author(s):  
Gao Lin ◽  
Wen-Bin Ye ◽  
Zhi-Yuan Li ◽  
Jun Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Spherical Shell ◽  
Three Dimensional ◽  
Theory Of Elasticity ◽  
Computational Domain ◽  
Content Type ◽  
Applied Loading ◽  
Surface Finite Elements ◽  
Element Method

Purpose The purpose of this paper is to present an accurate and efficient element for analysis of spherical shell structures. Design/methodology/approach A scaled boundary finite element method is proposed, which offers more advantages than the finite element method and boundary element method. Only the boundary of the computational domain needs to be discretized, but no fundamental solution is required. Findings The method applies to thin as well as thick spherical shells, irrespective of the shell geometry, boundary conditions and applied loading. The numerical solution converges to highly accurate result with raising the order of high-order elements. Originality/value The modeling strictly follows three-dimensional theory of elasticity. Formulation of the surface finite elements using three translational degree of freedoms per node is required, which results in considerably simplifying the computation. In the thickness directions, it is solved analytically, no problem of high aspect ratio arises and transverse shear locking can be successfully avoided.

Stiffness modelling of various types of atomic force microscopy cantilevers in 3D and validation of the models by finite element method

2017 ◽  
Vol 231 (4) ◽  
pp. 765-775
Author(s):  
MH Korayem ◽  
SD Ghahnaviyeh ◽  
MB Saraee
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Atomic Force Microscope ◽  
Three Dimensional ◽  
Critical Force ◽  
Three Dimensions ◽  
Torsional Stiffness ◽  
Three Dimensional Modeling ◽  
Atomic Force ◽  
Element Method

In the manipulations of nanoparticles in different environments, the manipulation dynamics have to be modeled precisely and the critical force and time of manipulation have to be computed. A dynamic manipulation modeling can be performed two- or three-dimensionally; and a three-dimensional modeling process is obviously more exact and complicated. In order to precisely model, in three dimensions, the dynamics of a nano-manipulation is performed by an atomic force microscope, where the stiffness values of various atomic force microscope cantilevers need to be calculated and modeled correctly. The cantilevers of an atomic force microscope are classified into three general groups (rectangular, V-shaped, and dagger-shaped) and each of these types is used for the manipulation of nanoparticles with particular characteristics. Also, in addition to the important application of stiffness in the dynamic modeling of a manipulation process, this model is very much needed in computing the critical force and time of manipulation, which are the two key parameters in the first phase of a manipulation. Due to the importance of the three-dimensional stiffness modeling of atomic force microscope cantilevers, first, the three-dimensional stiffness values of rectangular, V-shaped, and dagger-shaped cantilevers have been determined. The extracted stiffness models have then been validated by means of the finite element method. The comparisons between the stiffness values along different directions for the three mentioned types of cantilevers indicate that the V-shaped cantilever has the highest lateral stiffness, the dagger-shaped cantilever has the least amount of normal stiffness, and the rectangular cantilever enjoys the highest torsional stiffness.

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