Vector Preisach Model Research Articles

Simulation of uniaxial anisotropy by vector Preisach model

The paper presents a rotational single sheet tester, which can be used to measure vector hysteresis characteristics using specimen with round shape. The measured hysteresis characteristics in the two orthogonal directions present the uniaxial anisotropy of the material under test, which has been handled by the Fourier expansion of the measured Everett functions. The Fourier coefficients of the unknown vector Everett function have been identified by the modification of a previously implemented algorithm. In the identification task linearly and circularly polarized measured data have been taken into account. Comparisons between measured and simulated data show acceptable results.

Identification of the Parameters of Reduced Vector Preisach Model by Neural Networks

This paper presents a methodology for identifying reduced vector Preisach model parameters by using neural networks. The neural network used is a multiplayer perceptron trained with the Levenberg-Marquadt training algorithm. The network is trained by some hysteresis data, which are generated by using reduced vector Preisach model with preassigned parameters. It is shown how a properly trained network is able to find the parameters needed to best fit a magnetization hysteresis curve.

Design of 2D rrsst system by FEM withT, Φ-Φpotential formulation

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 H -coils and B -coils, respectively. The Finite Element Method (FEM) with the T, Φ-Φ 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.

First order reversal curves identification procedures for vector models of hysteresis

The first order reversal curves (FORCs) technique has been extensively used in the last years for the identification of parameters of Preisach-type models of hysteresis. The technique proved both accurate and robust for the identification of the Preisach distribution function but due to the relatively high computational complexity, it has only been applied to scalar models of hysteresis. The theoretical foundations of the procedure for the identification of parameters of vector Preisach models by using FORCs were established by Mayergoyz. However, to our knowledge, the numerical implementation of the technique has received very little attention in the literature and there is no experimental testing of this technique either. In this paper, we present for the first time results obtained for the identification of the vector Preisach distribution by using FORC diagrams for a magnetic tape with uniaxial anisotropy. We also tested the model with simulated data produced by a vectorial Preisach model in which the pseudoparticles’ equilibrium state was calculated with a Landau–Lifshitz–Gilbert algorithm.

A New Identification and Implementation Procedure for the Isotropic Vector Preisach Model

A factorable Preisach distribution function is a reasonable assumption in modeling soft magnetic materials. With this assumption it is possible to define and employ a single-input Preisach function for easier implementation and identification of a scalar Preisach model. On the basis of this simplification, we developed a new method for identification and implementation of the isotropic vector Preisach model. With the aid of a newly derived equation, the Preisach function of the vector Preisach model can be identified from the corresponding scalar one. We verified the correctness of the proposed method by comparing the results of scalar and vector models in a scalar condition of input variation.

Simulation of a vector hysteresis measurement system taking hysteresis into account by the vector Preisach model

The paper deals with the numerical analysis of a rotational single sheet tester with round-shaped specimen (RRSST) which is now under construction. The measurement setup consists of an induction motor the rotor of which has been removed, and its windings have been replaced to a special two phase one which can generate homogeneous magnetic field inside the motor. The two orthogonal components of the magnetic field intensity and of the magnetic flux density vectors can be measured by H-coils and B-coils, respectively. The Finite Element Method (FEM) with the T , Φ–Φ potential formulation has been applied in the simulations. The vector hysteresis property of the specimen has been approximated by the vector Preisach model. Finally, the nonlinear problem has been solved by the fixed-point technique. The aim of the present work is to focus on the design aspects of this kind of measurement system.

Numerical analysis of a 2D vector hysteresis measurement system

This paper deals with the numerical analysis of a vector hysteresis measurement system, which is under construction in the laboratory. The aim is to build up a single sheet tester with round shaped specimen. The goal of simulations is to find out the main features of the measurement system. The 3D finite element method (FEM) with tetrahedral mesh developed in the laboratory has been applied for investigations of the nonlinear eddy current field problem. The characteristic of the magnetic material has been taken into account by the isotropic vector Preisach model. The nonlinearity has been handled by the polarization method and the nonlinear system of equations has been solved by the fixed-point technique. The first results are presented in this work.

A Preisach-Stoner–Wohlfarth Vector Model

In previous papers we presented a new model of vector hysteresis, called RVM. The crux of the model is the definition of a vector hysteron, described in the H-space, and limited by a closed critical surface. Generally, the critical surface may be any closed simply connected surface, such that each surface point has a unique surface normal. The magnetization computed should be a conservative function of the applied field, and constant in magnitude. This paper proposes a new model, called the PSW vector model, for the magnetization outside the critical surface. It is a generalization of the RVM based upon the merging of the vector Preisach model and the Stoner-Wohlfarth model.

A vector Preisach model combined with a Newton–Raphson method for transient magnetic field computations

This paper presents a computational approach for transient magnetic field problems with vector hysteresis. A nonlinear update scheme is given to improve the convergence of the nonlinear iteration in the particular hysteresis case, in combination with the finite integration implicit time domain formulation. A simplified vector Preisach model is coupled with the Newton–Raphson method for handling magnetic nonlinearities. The Newton–Raphson method equipped with a relaxation strategy is used for linearization. The proposed computational approach is validated by means of a transformer model three-limbed ferromagnetic core exhibiting alternating and rotating fluxes.

Magnetic force computation with hysteresis

PurposeThe purpose of this paper is to present a procedure, which determines the magnetic force acting between a soft magnetic cylinder and a coil taking the hysteresis phenomena into account.Design/methodology/approachThe magnetic force is computed replacing the ferromagnetic body with an equivalent magnetic moment distribution. Isotropic vector Preisach model with analytical expressed Everett function describes the magnetic properties of the ferromagnetic material. The magnetization distribution is calculated applying the integral equation method. The Preisach hysteresis model is included in the iteration process based on Picard‐Banach scheme.FindingsIn the case of integral equation method the unknown quantities are the magnetization and the magnetic field intensity. In this way the Preisach hysteresis model can be included in a convenient way in the iteration procedure. Knowing the magnetization distribution the magnetic force can be determined. The developed algorithms can be applied in tubular linear motor design.Originality/valueThe paper presents a new formulation of the Preisach hysteresis model. With the aim of the analytically expressed Everett function a stable and faster algorithm can be realized to determine the magnetic force in arrangements with ferromagnetic parts.

On the reduced vector Preisach model of hysteresis

We discuss the use of a reduced vector Preisach model (RVPM) as a numerical tool for the analysis of vector rotating and alternating magnetic fields. In particular, we discuss the possibility of computing the vector fields using a fast procedure when the Preisach functions is factorable and the material is a single-quadrant medium along the principal axes. In addition, we discuss the behavior of the RVPM model for two different analytical Preisach distributions, whether they are factorable or not, and show that the model needs a correction factor, even for an isotropic media.

Properties of vector preisach models

We discuss rotational anisotropy and rotational accommodation of magnetic-particle tape, phenomena that affect performance during reading and writing in the recording process. We introduce the reduced vector Preisach model (RVPM) to simplify the selection rules and eliminate the rotational correction of the simplified vector Preisach model (SVPM). In order to make the model agree with our measurements, we introduce the RVPM, which eliminates the need for a rotational correction in the SVPM. Using this new model as a basis to characterize the medium, we have measured and computed the angle of magnetization for a magnetic-particle tape rotated in an applied field. Because rotational models must accurately compute the anisotropic characteristics of ellipsoidally magnetizable media, we use an ellipticity factor that accurately computes the two-dimensional magnetization trajectories for small applied fields, and that corrects the orientation error for both isotropic and anisotropic media. We report rotational magnetization measurements that demonstrate vector accommodation for ellipsoidally magnetizable media. The magnetization trajectories show that accommodation is achieved.

Identifying the Parameters of the Reduced Vector Preisach Model: Theory and Experiment

In this paper, we discuss the use of a reduced vector Preisach model for a preliminary analysis of rotating hysteresis in laminated Fe-Si steels. In particular, we present a simplified identification procedure based on the assumption that the material is single quadrant along the principal axis. We discuss the use of a numerical technique for the identification of the model parameters using hard and easy axis measurements.

Modeling of laminas of magnetic iron with a Reduced Vector Preisach Model

In this paper we use a Reduced Vector Preisach Model for a preliminary analysis of rotating hysteresis in laminated Si–Fe steels. After the description of the main facts about the vectorial hysteresis modeling and the formulation of the cross coupling Preisach functionals, we present here a numerical technique for the identification of the model using the hard and easy axis measurements. An applicative example for non oriented grain steels is presented.

Rotational magnetization losses in vector models

Unlike the case of an oscillating magnetic field, power losses in a magnetic material eventually start decreasing as the magnitude of a rotating field increases. In some hysteresis models, the loss increases monotonically as the magnitude of a rotating field increases. The simplified vector Preisach model and the reduced vector Preisach model do not suffer from this error. For magnetization-dependent reversible models, such as the Della Torre-Oti-Kadar, and for state-dependent models such as the complete moving model, the loss per cycle has two components. The first is computed from the Preisach integrals, and the second is computed from the change in the stored energy in the reversible component. It is noted that the latter loss can occur even if there are no Barkhausen jumps. This article discusses the details of how the model accomplishes this.

Comparison of measurements with simplified vector preisach model computations

A simplified vector Preisach model is used to compute the magnetization of anisotropic media using Preisach parameters identified along the principle axes of the media. A cobweb array approach is used to discretize the Preisach planes. A comparison is made of computed magnetization from the model with measured magnetization from a vibrating sample magnetometer.

Core loss estimation in three‐phase transformer using vector hysteresis model and classical loss model incorporated in 2D magnetodynamics

AbstractThis paper deals with the computation of the magnetic field and core loss in a three‐phase three‐limb transformer at no‐load. The computational algorithm consists of the vector hysteresis model incorporated in 2D magneto‐dynamics via the differential reluctivity tensor. The hysteretic nonlinearity is handled by a simple iteration scheme. The eddy‐current losses in the laminated steel core are accounted for by considering an additional conductivity matrix in the FE equations. The magnetisation‐dependant vector Preisach model with an analytical expression for the distribution function is adopted for describing the hysteretic constitutive law in the rolling and transverse directions of the laminations. The parameters and mean field term are fitted on the basis of a set of BH‐symmetric (quasistatic) loops. Numerical results are presented that confirm the effectiveness of the proposed method for the no‐load simulation of the transformer in the transient and the steady‐states.

On hysteresis in elasto-plasticity and in ferromagnetism

We define hysteresis as rate-independent memory, illustrate some of its properties, and review some scalar models of elasto-plasticity: the stop, the play, the Prandtl–Ishlinskiı̆ models. In particular we study the Prager model of linear kinematic hardening, which encompasses stops and plays. We then couple the latter model with the dynamic equation for a one-dimensional system, show existence of a weak solution, and deal with its homogenization. We also discuss the extension to tensors and to three-dimensional systems. We then deal with ferromagnetic hysteresis. We review the classic Preisach model and a vector extension. Finally, we formulate a model of vector ferromagnetic hysteresis, couple it with the magnetostatic equations, and discuss its homogenization. The latter consists in a two-length-scale model, and corresponds to a variant of the vector Preisach model.

Identification procedures of Preisach model

This work deals with the comparison of two identification procedures of Scalar and Vector Preisach Model. The first one is to assume a Preisach function and determine the different parameters with the knowledge of the remanence and the coercivity. The second one is to measure the Everett function directly.

Implementation of the simplified vector model

The simplified vector Preisach model (SVPM) is a three-dimensional (3-D) magnetization model developed for fast computations. In this paper, a new algorithm for the SVPM is detailed, which accomplishes two goals: 1) to extend the model from a two-dimensional to a 3-D model and 2) to provide efficient implementation of the model.