The paper deals with the numerical analysis of a vector hysteresis measurement system, which is now under construction. The measurement set up consists of an induction motor whose rotor has been removed, and its windings have been replaced to a special two phases one, which can generate a homogeneous magnetic field inside the motor. A round shaped specimen can be inserted into the arrangement. The two orthogonal components of the magnetic field intensity and of the magnetic flux density vectors can be measured by
-coils, respectively. The Finite Element Method (FEM) with the
potential formulation has been applied in the simulations. The vector hysteresis property of the specimen has been approximated by the isotropic vector Preisach model, finally the nonlinear problem has been solved by the convergent fixed point technique. The aim of the present work is to focus on the design aspects of this kind of measurement system.
The paper deals with an eddy current field problem as a case study. The aim is to find the solution of the problem by the help of the Finite Element Method (FEM), and the
T, Φ, Φ
potential formulation taking the nonlinearity of the material into account. The effect of nonlinearity has been approximated with an inverse tangent type analytical model. The nonlinearity has been handled by the polarization method coupled with the Fixed-point iteration technique.
The paper deals with the analysis of the single-phase induction motor of Problem No. 30a of the COMPUMAG TEAM Workshop. The problem has been solved by the motional two-dimensional time-harmonic Finite Element Method (FEM) using different potential formulations, the
, -potential formulation and the
-potential formulation. Here the problem is a linear eddy current field problem.
The paper presents and compares three potential formulations to solve nonlinear static magnetic field problems by applying the fixed-point technique and the Newton-Raphson scheme. Nonlinear characteristics have been handled by the polarization method in the two algorithms. The proposed combination of Newton-Raphson scheme and the polarization formulation result in a very effective nonlinear solver, because only the derivate of the characteristics, i.e. only the permeability or the reluctivity has to be used. That is why, this method can be prosperous to solve nonlinear problems with hysteresis, and it is faster than the classical fixed-point method.
A comprehensive analysis of the finite element method based lamination modeling has been performed and the results are presented in this paper. The simulations are made in two subsequent steps. In the first step, the approximate magnetic field distribution inside the material with linear characteristics is determined assuming a bulk material having anisotropic conductivity and laminates are not taken into account. In the second step, the eddy current field inside the individual laminates is modeled. The boundary conditions of any individual sheets are obtained from the bulk model. The paper presents the advantages and the drawbacks of the applicable potential formulations. Results are compared with the quasi-static electromagnetic field obtained from a reference solution taking account of each laminate.
The numerical analysis or design of an arrangement, which require electromagnetic field calculation, can be characterized by the electric and magnetic field intensities and flux densities. For determination of these field quantities in the electromagnetic field, one method is to find the solution of the partial differential equations of the field quantities under prescribed boundary conditions obtained from Maxwell’s equations. The Finite Element Method (FEM) is a possible technique to solve partial differential equations, which is based on the weak form of the weighted residual method. The paper presents some potential formulations, which can be used for solving static magnetic field problems and eddy current field problems with the help of FEM. Some examples are also presented at the second part of the paper.
Krebs G., Henneron T., Clénet S., Buhan Y. L. Overlapping finite elements used to connect non-conforming meshes in 3D with a vector potentialformulation, IEEE Transactions on Magnetics , Vol. 47, No. 5, 2011, pp. 1218