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This article presents the modified Preisach model of hysteresis for a 3-phase medium frequency transformer in a 100 kW dual active bridge converter. The transformer magnetic core is assembled out of ferrite I-cores, which results in multiple parasitic air gaps. For this transformer, the hysteresis loops were measured and parameters of the Preisach model were determined. The Preisach distribution function is approximated with a two-dimensional Gauss function series and the feedback function is a 3rd-degree polynomial. The optimized identification of Preisach distribution function parameters was prepared. Two sets of parameters were determined based on the analysis of major and minor hysteresis loop. The developed model is used to analyze the transformer core power loss. A new set of Steinmetz equation parameters for multi air gap ferrite core MFT is proposed.

This paper presents a simple dynamic vector-play model to calculate the iron loss and describe the vector hysteresis behavior of a non-oriented (NO) electrical steel sheet (ESS) under 50 Hz rotating magnetic fields. Based on the iron loss separation theory, the proposed model is separated to the static hysteresis component and eddy current component. The static hysteresis component is constructed by vector play model, which is identified by using 1 Hz minor $B$ – $H$ loops. And two coefficients $\omega _{x}$ and $\omega _{y}$ are introduced to consider the anisotropic property of NO ESS and the excess loss of eddy-current component under 50 Hz magnetic field. The validity of the proposed dynamic vector hysteresis model is verified by comparing it with the experimental results under various 50 Hz magnetic field conditions.

An anisotropic vector hysteresis model based on the improved isotropic vector play operator has been presented to predict the magnetization behavior of anisotropic hysteresis materials. The required parameters can be identified from the major hysteresis loops in all principal axes, which can be easily measured, or are directly available from magnetic material manufacturers. The presented model, which has been successfully implemented in 2-D and 3-D transient finite-element analysis, is validated by numerical experiments and measured data cited from TEAM problem 32, and is applied to simulate a synchronous reluctance motor with an axially laminated anisotropic rotor.

Hysteresis characteristics of the general Spin-S (S > 1) Blume-Capel model have been studied within the effective field approximation. Particular emphasis has been paid on the large negative valued crystal field region and it has been demonstrated for this region that, Spin-S Blume-Capel model has 2S windowed hysteresis loop in low temperatures. Some interesting results have been obtained such as nested characteristics of the hysteresis loops of successive spin-S Blume-Capel model. Effect of the rising crystal field and temperature on these hysteresis behaviors have been investigated in detail and physical mechanisms have been given. (C) 2017 Elsevier B.V. All rights reserved.

This paper presents an improved identification algorithm of the scalar play model, and suggests a novel vector play model to describe the vector hysteretic behavior of a nonoriented electrical steel sheet (ESS) under rotating magnetic fields. The proposed identification algorithm gives much better numerical accuracy than a conventional one by assigning more play operators than the measured asymmetric minor loops. The vector-shape function of the suggested vector play model consists of two scalar shape functions, which are independently identified by using measured hysteresis loops under alternating magnetic fields along rolling and transverse direction of ESS, respectively. The vector play model, furthermore, employs a nonlinear coefficient, which is a function of the magnitude and direction of magnetic flux density, to increase the numerical accuracy. The validity of the suggested vector play model is verified by comparing it with experimental results under various magnetic-field conditions.

This paper presents a novel algorithm for the computation of transient electromagnetic fields in nonlinear magnetic media with hysteresis. We deal with an axisymmetric transient eddy current problem where the constitutive relation between H and B is given by a hysteresis operator, i.e., the values of the magnetic induction B depend not only on the present values of the magnetic field H but also on its past history. First, we introduce the mathematical model of the problem and, by applying some abstract result, we show the well posedness of a weak formulation written in terms of the magnetic field. For the numerical solution, we consider the Preisach model as hysteresis operator, a finite element discretization by piecewise linear functions, and the backward Euler time discretization. By taking into account the monotonicity property of the Preisach model, we propose a fixed point algorithm to deal with hysteresis effects which is numerically validated: we report a numerical test in order to assess the order of convergence and we compare the results with experimental data. For the later, we consider a physical application: the numerical computation of eddy current and hysteresis losses in laminated media as those used in transformers or electric machines. HighlightsMathematical analysis and numerical implementation of an axisymmetric parabolic problem with hysteresis.A novel algorithm in order to handle the hysteresis (classical Preisach) operator is presented.The algorithm can be used in the above mentioned parabolic problem with a smooth (not necessarily periodic) source term.Algorithm takes advantage of the spatial independence of the hysteresis operator, handling its lack of differentiability.Numerical results are compared with experimental data. Moreover, a test to assess the convergence order is included.

Power converters often features inductive devices in their architectures. Accurate simulation of the converters requires a well-defined response of the magnetic cores. A computationally efficient approach for the numerical modelling of hysteretic magnetic materials is presented in this work. The approach exploits the simplicity of the identification procedure for the Preisach model of hysteresis and the reduced computational costs of Neural Networks. The model for hysteresis is implemented both in direct and inverse form. Validation is performed against independent dataset, with evident computational speedup, which can be a valuable asset for magnetic cores simulations in the design of complex power systems featuring multiple converters such as the ones used in avionic applications.

The Preisach model of hysteresis admits simple device realizations. It is suggested in the paper that these realizations can be utilized as unique data storage devices as well as analog global optimizers.

A computationally efficient and robust neural network-based model to reproduce the hysteresis phenomenon for soft ferromagnetic alloys is here presented, as well as a dedicated procedure to generate a suitable training set from a minimal set of experimental data. Firstly, an accurate experimental verification has been performed for a commercial NGO electrical steel, measuring a family of hysteresis loops under sinusoidal and non-sinusoidal magnetic induction waveforms. The Preisach model of hysteresis, identified with the sinusoidal loops, has been exploited to generate a wider data set, which consists of a family of first-order reversal curves (FORCs), suitable to train the neural network. Then, a neural network-based hysteresis model, with the capability to reproduce the eventual presence of sub-loops, has been developed. The two simulation approaches have been validated taking into account the other experimental data, which consist of a family of hysteresis loops measured under different types of magnetic induction waveforms. The comparison between the Preisach model and the neural network-based model also covers the simulation of the waveforms found in magnetic systems supplied by pulse-width modulated (PWM) signals. The substantial agreement found indicates that the neural network model can replicate the behaviour of the Preisach model with a considerable advantage in terms of computational cost and memory allocation. In addition, the possibility to be quickly inverted makes the proposed method suitable for matching with FEM solvers.

International audience; We propose an original approach to solve the coupled problem of alternative magnetic field penetration inside a toroidal soft ferromagnetic sample and frequency dependent magnetic hysteresis. Local repartition of ferromagnetic losses depends on the instantaneous material properties and on the frequency of the excitation field waveform. A correct solution to the model, with respect to this repartition, implies a higher resolution in two dimensions of the diffusion equation including local dynamic hysteresis consideration. The resulting model gives precious local information but requires complex parameter setting, high computational capacity and long simulation time. Due to the toroidal shape, a single dimension algorithm solving of the diffusion equation is clearly insufficient and it would lead to inaccurate simulation results. Consequently, a large number of discretization nodes and extended simulation time must be considered in two dimensional configurations. In our alternative solution, starting from a lumped model, we add a fractional time derivative of the dynamic hysteresis losses. It leads to an accurate formulation of the problem with a reduction in complexity and simulation times.

This paper deals with the models elaboration for the asymmetric three-phase transformers. The first model uses the principle of the hysteresis integration in two-dimensional finite-element method (FEM) with magnetic field calculations. This method is based on inverse Jiles–Atherton hysteresis model. The second one is a dynamic electromagnetic model (DEM) based on Tellinen hysteresis model. The DEM and FEM models used in ferromagnetic cores have been modified by replacing the anhysteretic curve by the hysteresis loop. A simulation in time domain is carried out and the simulated results are compared with those obtained experimentally to validate the proposed approach. An error calculation is performed to show the accuracy of results obtained by DEM and FEM models.

This paper compares two different identification methods of a static rate-independent energy-based hysteresis model with regard to the dynamic hysteresis loop shape prediction when coupled to the parametric magnetodynamic lamination model. The values of hysteresis model parameters are determined solely based on the quasi-static major loop. A semiphysical approach identifying the reversible and irreversible field components independently and a purely mathematical scheme using a differential evolution optimization algorithm determining all parameters simultaneously are compared. Both variants of parameter identification are analyzed in terms of hysteresis loop shape prediction for quasi-static as well as dynamic loops.

This paper deals with the implementation of an energy-consistent ferromagnetic hysteresis model in 2D finite element computations. This vector hysteresis model relies on a strong thermodynamic foundation and ensures the closure of minor hysteresis loops. The model accuracy can be increased by controlling the number of intrinsic cell components while parameters can be easily fitted on common material measurements. Here, the native h-based material model is inverted using the Newton-Raphson method for its inclusion in the magnetic vector potential formulation. Simulations are performed on a 2D T-shaped magnetic circuit exhibiting rotational flux. By way of validation, results are compared with those obtained with the dual magnetic scalar potential formulation. A very good agreement for global quantities is observed. ispartof: IEEE Transactions on Magnetics vol:52 issue:3 pages:1-4 ispartof: location:CANADA, McGill Univ, Montreal status: published

Amorphous ferromagnetic Fe-based microwires (MWs) have a magnetic structure consisting mainly of a single longitudinal domain and small closure domains at both ends. A rectangular hysteresis loop is then observed according to the fast domain wall propagation along the microwire. This type of material is a good physical example of the idea of a magnetic relay hysteron as described in Preisach model of hysteresis. The hysteron was defined as a mathematical operator acting on the field and producing rectangular loops whose superposition gives out the hysteresis loop. The hysteron idealization is frequently used to describe and interpret FORC (First Order Reversal Curve) diagrams by comparison with Preisach plane. The central idea of this work is to study the FORCs of a real physical sample that behaves closely to the ideal hysteron, both isolated and interacting with a twofold aim. On one hand, providing a better understanding of FORC measurements, and, on the other, analyzing the magnetization reversal processes in microwires with rectangular hysteresis loops. While for a single microwire the behaviour is that expected for a hysteron, both in the hysteresis loop and in the FORC diagram, the magnetostatic interaction between two microwires breaks with the ideal behaviour due to the change in the domain wall mobility at the end of the wires.

This paper describes a system for training healthcare practitioners in the identification of different arterial pulses. The driving system uses a linear solenoid in an open loop force control. Due to the large hysteresis it exhibited, a form of compensation was implemented, based on the classic Preisach model of hysteresis. Implementation of said model resulted in a significant reduction of force tracking error, demonstrating the feasibility of the chosen approach for the intended application.

In order to reduce the partial derivative errors in Preisach hysteresis model caused by inaccurate experimental data, the concept and correlative method of discretization of Preisach hysteresis model are proposed, the essential of which is to centralize the distribution density of Preisach hysteresis model in local region as an integral, which is defined as the weight of a certain point in that region. For the input composed of an ascending segment and a descending segment, a method to determine the initial weights together with an additional method to determine present weights is given according to the number of input ascending segments. If the number of input ascending segments increases, the weights of the corresponding points in updating rectangle are updated by adding the initial weights of corresponding points. A prominent advantage of discrete Preisach hysteresis model is its memory efficiency. Another advantage of discrete Preisach hysteresis model is that there is no function in the model, and thus, it can be expediently operated using a computer. By generalizing the above updating rectangle method to the continuous Preisach hysteresis model, identification method of distribution density can be given as well.

The extended Preisach model is used extensively in precision control for its ability to model and thus can be used to suppress the hysteresis phenomenon. Although an inverse model based on the classical Preisach model entails a very high level of computational complexity, recent advances in computer technology has enabled real-time implementation of such models. The extended Preisach model calculates the hysteresis action by fitting the - table in the Preisach model to a surface. One can then calculate the amount of extension and retraction simply by searching for the parameters on the surface. This paper proposes a real-time high speed implementation of a model-based hysteresis elimination control. The experimental results show that the proposed method produces a smaller tracking error with a smooth system output.

The paper developed computation method to predict the behavior of hysteresis loops via an explicit function. Based on the Fermi–Dirac statistics and assumption of magnetic domains as fermions, formulations to successfully explain magnetic hysteresis loop are devoted. The capability of the new model to calculate the characteristics of magnetic hysteresis loop was tested by comparing the experimental results of both the variation of magnetic induction with magnetic field intensity and variation of magnetization along magnetic field intensity. The results of the application of the new model confirm the reliability of the procedure. The differences between the calculated and the measured data are always less than the data tolerance usually declared by the experiments. Particular attention to the influences of temperature on the parameters in the explicit function results in determination of magnetization of fixed ferromagnetic material by both magnetic field and temperature. Besides, the paper shows that coercively of ferromagnetic materials can be indicated by temperature. The technique given in this paper is found to be very advantageous for understanding the hysteretic problems.

This paper shows that a Preisach engine, based on the classical Preisach model of hysteresis and identified using the Everett integrals and the first-order reversal curves, can be used whatever the orientation of the hysteresis loop [counterclockwise or clockwise] and whatever the monotonicity of the branches (increasing/decreasing). This is important for the use of the Preisach model in many innovative applications, such as hysteresis compensators in magnetostrictive devices and lithium-iron-phosphate rechargeable battery, as both the applications are characterized by clockwise hysteresis loops and strictly increasing loop branches. Numerical simulations of both cases, compared with experimental data, prove the validity of the approach.

A magnetic hysteresis model is developed based on the vector generalization of Jiles–Atherton (JA) model combined with a simplified multiscale approach to take into account the effect of mechanical stress on the magnetic behavior. The model aims at representing electrical steel behavior under any loading configuration considering the magnetic field vector and the mechanical stress second-order tensor. Mechanical stress is introduced in the JA hysteresis model through the anhysteretic magnetization and a modified pinning parameter. The main properties of the model are shown under alternating and rotating applied induction, especially in terms of hysteresis losses. The differential magnetic susceptibility is derived from the model, and the implementation into a time-stepping finite-element method is detailed. Finally, a quasi-statically rotating switched reluctance motor is studied: considering different shrink-fitting conditions, the resulting stress is shown to have a significant effect on both distribution and global value of hysteresis losses.

In the present paper, the Preisach model of hysteresis is extended to structural analysis of trusses damaged under cyclic loading in plastic range. Parameters for the Preisach model of cyclic plasticity are obtained from uniaxial loading experiment. Damage, as a consequence of micro cracks appearance due to alternating loading in plastic domain, is modeled using brittle elements according to Preisach procedure. Results of this research are compared with the already existing in the literature. In the paper examples of trusses under various cyclic loadings are presented. Applied Mechanics and Materials

The laminated core is tested under sinusoidal and dc-biased magnetizations. The measured data are manipulated by the proposed modified iterative method to obtain dc-biasing hysteresis loops accurately. The hysteresis model, based on a consuming function, is used to simulate the hysteresis effects of the iron core under different magnetizations. The fixed-point technique is combined with the harmonic-balanced method to compute exciting currents and magnetic fields simultaneously by considering the hysteresis effects. The global convergent strategies are presented to guarantee the convergence of harmonic solutions. The hysteretic characteristics and iron loss of the laminated core are analyzed on the basis of harmonic solutions of the magnetic field.

Hysteresis models can incorporate the effects of operating conditions (frequency, stress, and temperature) on iron losses incurred in ferromagnetic materials. Among such models, the Jiles–Atherton (JA) and Preisach models are the most popular and various modifications of these have been proposed in the literature to model the effect of frequency, stress, and temperature on iron losses. Both of these representations produce accurate results compared with the curve fitting models and can be directly implemented in finite element simulations. Unfortunately, it is very difficult to incorporate all these effects into a single iron loss model that is computationally efficient and can predict iron losses with reasonable accuracy for a given range of these parameters. In this paper, an effort has been made to establish a relationship between JA and Preisach models and an interpolation-based approach is presented to predict iron losses that utilizes the Preisach model on top of the JA model and incorporates all of the above factors. It is shown that iron loss can be predicted accurately for any value of frequency, stress, and temperature.

We study the response of Preisach models of hysteresis to stochastically fluctuating external fields. We perform numerical simulations which indicate that analytical expressions derived previously for the autocorrelation functions and power spectral densities of the Preisach model with uncorrelated input, hold asymptotically also if the external field shows exponentially decaying correlations. As a consequence, the mechanisms causing long-term memory and 1/f-noise in Preisach models with uncorrelated inputs still apply in the presence of fast decaying input correlations. We collect additional evidence for the importance of the effective Preisach density previously introduced even for Preisach models with correlated inputs. Additionally, we present some new results for the output of the Preisach model with uncorrelated input using analytical methods. It is found, for instance, that in order to produce the same long-time tails in the output, the elementary hysteresis loops of large width need to have a higher weight for the generic Preisach model than for the symmetric Preisach model. Further, we find autocorrelation functions and power spectral densities to be monotonically decreasing independently of the choice of input and Preisach density.

We call attention to a dual-pair concept for modeling hysteresis involving instantaneous switching: Specifically, there are two input–output pairs for each hysteresis model under one specific input, namely a differential pair and an integral pair. Currently in engineering mechanics, only one pair is being recognized and utilized, not the other. Whereas this dual-pair concept is inherent in the differential and algebraic forms of memristors and memcapacitors, the concept has not been carried over to memristive system theory, nor to memcapacitive system theory. We show that the “zero-crossing” feature in memristors, memcapacitors, and memristive/memcapacitive models (i.e., the “mem-models”) is also a feature of the differential pairs of well-known non-mem-models, examples of which are Ramberg–Osgood, Bouc–Wen, bilinear hysteresis, and classical Preisach. The dual-pair concept thus connects mem-models and non-mem-models, thereby facilitating the modeling of hysteresis, and raising a set of scientific questions for further studies that might not otherwise come to awareness.

Robust tracking control of shape memory alloy (SMA) systems is a challenge because of their highly non-linear response, non-local memory and lack of differentiability. In this work, a linear parameter-varying (LPV) control method is proposed to compensate for the hysteretic behaviour of an SMA actuator. To provide information on the scheduling variable, the Preisach model of hysteresis is utilised. Parameter-dependent controller is updated based on the real-time computation of the instantaneous scheduling variable from the model. An H ∞ controller is also synthesised by representing the hysteresis as a parametric uncertainty. The controllers are implemented on an SMA actuated experimental system. Experimental validation is conducted for various types of reference inputs which can dramatically change the system's response. These reference signals are designed to excite major, minor and frequency dependent hysteresis loops. Trajectory tracking and disturbance rejection results show that the LPV controller has an improved response and the hysteresis is compensated for the full range of the scheduling variable. The tracking performances of both controllers are also compared when the system is under partial and persistent plant disturbances. For these cases, the LPV controller results in a more robust tracking response because of its less conservative structure.

This paper presents a predictive and easily implementable hysteresis model for ferromagnetic laminations subjected to various quasi-static magnetic loads. In this model, the description of magnetic hysteresis is based on the decoupling of the magnetic field strength in a reversible and irreversible part, unlike in the Jiles-Atherton model. Thereby, the source of problems originating in the assumption that total magnetization could be split into the reversible and the irreversible component is bypassed. It should be stressed that models based on field separation principles are consistent with the laws of thermodynamics. The presented model allows for a systematic parameter identification based on standard magnetic measurements. In this paper, the variation of model parameters on the shape of the modeled hysteresis loop is presented. Furthermore, parameter identified from the major loop are applied to model symmetric minor loops that are evaluated by comparison with measurements. The structure of the model enables an inclusion of eddy-current effects, and is ready for a further exploitation in the FE modeling of macroscopic devices.

This paper presents a model for calculating the hysteresis loss in electrical machines. The model can achieve accurate and computationally efficient hysteresis loss calculations by utilizing both analytical equations and the Energetic hysteresis model. The model results are verified experimentally by comparing to a series of minor hysteresis loop measurements. The hybrid model is then implemented to calculate the core losses in a switched reluctance (SR) machine using finite element (FE) simulation. The results show that precise machine core loss prediction requires having a model that is capable of calculating the hysteresis losses under a variety of minor hysteresis loops.

History-dependent and history-independent models of magnetic hysteresis are proposed. Spline approximations to the magnetization curves make these models applicable to major loops of any shape. The H(B) representation of reversal curves permits the development of a method that generates reversal curves guaranteed to be free from nonphysical negative slopes and excursions outside the major loop. The applicability of the models to electrical steels and a powder core is illustrated.

Magnetic materials with large coercive force and high squareness ratio are currently developing to meet an industrial demand. Since a ferromagnetic material has hysteresis characteristics, it is hard to demagnetize a ferromagnetic material precisely. In this paper, we describe deperm processes and conduct an analysis of residual magnetization of ferromagnetic material using the Preisach modeling with a two-dimensional finite elements method (FEM). From the results, it was shown that an exponential decrement form of deperm protocol is more efficient than a linear decrement form because of the demagnetizing field in the ferromagnetic material.

In this paper, we discuss the numerical modeling of hysteresis in magnetic steels with oriented and nonoriented grain. The modeling is fully 3-D, but it is applied here to typical 2-D magnetic problems. Starting from a vector generalization of the Preisach model, we introduce here the concept of an operative magnetic field, function of the state of magnetization of the material. This operative field is introduced to reproduce with more accuracy the peculiar behavior of Si-Fe steels approaching the saturation state. The properties of the model are discussed and some examples are reported.

In this paper, we present a benchmark problem for the validation of numerical models of vector magnetic hysteresis. The problem geometry and the measurement system are described. The materials considered are both oriented grain (OG) and not OG Si-Fe steels. A series of experimental data about magnetic field and magnetic induction loci under rotational magnetization are presented with the corresponding magnetic losses. The measured data can be useful as a reference for the numerical models testing, comparison, and development. In addition, we propose here a comparison of the experimental data with the numerical results computed using a vector hysteresis model based on the extension of the Preisach model in 2-D.

Irreversible thermal demagnetization effects can sometimes play a significant role in, for instance, rotating Preisach model (PM) machines. Modeling such phenomena requires field simulation methods such as finite element (FE) analysis in combination with a temperature-dependent vector hysteresis model. This paper explores the feasibility of applying a formalism for temperature-dependent structural hysteresis to magnetics. The net magnetization is expressed as a superposition of contributions from plays. By allowing the anhysteretic curve and the coercivity to depend on temperature, irreversible thermal effects resembling experiments emerge automatically without additional assumptions or adjustable parameters. Incorporating this temperature dependence has negligible impact on the computational efficiency or complexity of the model.

Iron parts of electrical machines are made of nonoriented isotropic ferromagnetic materials. The finite element method (FEM) is usually applied in the numerical field analysis and design of this equipment. The scalar Preisach hysteresis model has been implemented for the simulation of static and dynamic magnetic effects inside the ferromagnetic parts of motors. The dynamic model is an extension of the static one; an extra magnetic field intensity term is added to the output of the static inverse model. This is a viscosity-type dynamic model. The fixed point method with stable scheme has been realized to take frequency-dependent anomalous losses into account in FEM. This scheme can be used efficiently in the frame of any potential formulations of Maxwell's equations. The comparison between measured and simulated data using a toroidal core shows a good agreement. A modified nonlinear version of T.E.A.M. Problem No. 30.a is also shown to test the hysteresis model in the FEM procedure.

A new hysteresis model is developed to describe clockwise hysteresis, in which the positive saturation is achieved for positive values of the input. The model is based on the traditional (counter-clockwise) Jiles-Atherton (JA) model and describes the input-output relation in the form of a first-order differential equation. The most important characteristics such as initial susceptibility, coercive fields, remanence, thermal stability, first and higher order reversal curves are discussed. A comparison with other two clockwise hysteresis models of hysteresis (i.e., the Preisach and Bouc-Wen models) is provided. It is proven that the clockwise JA model can describe novel hysteretic behavior that cannot be reproduced by the previous two models. The novel model is also appealing due its relatively simple numerical implementation and its small number of parameters.

This paper proposes a different inverted hysteresis model with modification of the classic Preisach switch operator. By using this new switch operator, the inverted model remains the wiping out and congruency properties. It also guarantees the symmetry and total positiveness of weight function in the Preisach plane. According to the change pattern of H(B) branches, a differentiable weight function is introduced in the inverted model. The weight function performs with good continuity and symmetry. This makes it possible to implement the inverted model in numerical analysis without iterative procedure. The identification work is done by means of the measured major loops. Here the Newton method algorithm is applied to optimize the mean squared error (MSE) between the measured and simulated data. By this way, the limited number of parameters can be determined. The inverted model was verified for both soft and hard magnetic materials. Besides major hysteresis loops, minor loops and first-order reversal curves (FORCs) can also be simulated. By comparison, the simulation results produced by the inverted hysteresis model show good approximation to the measurement data.

In this paper, a study on the demagnetization of ferromagnetic materials is conducted based on both experiments with magnetic treatment facility (MTF), which is a miniaturized experimental model, and numerical analysis methods in which the static magnetic finite-element method and Preisach model are combined. The magnetic hysteresis phenomenon inside ferromagnetic materials is effectively mimicked by means of Preisach model. However, owing to the use of $M\hbox{-}H$ variables, Preisach model generally bears numerical instability during repetitive computations. A Preisach model with $M\hbox{-}B$ variables is proposed in this paper to resolve the numerical instability. From the proposed Preisach model with $M\hbox{-}B$ variables, analysis results that were tantamount to those from the general Preisach model with $M\hbox{-}H$ variables were obtained. Numerical instability was also resolved by the proposed model. Furthermore, the discrepancy was practically negligible between the experimental result from a practical demagnetization process and the numerical analysis result from the proposed Preisach model with $M\hbox{-}B$ variables, under the same conditions.

A method for the analysis of high-speed hysteresis micromotor by using a magnetostatic field solution and Piece-Wise-Linear (PWL) model of scalar static hysteresis is presented. The solution of the magnetic field in the active layer of the hysteresis motor is performed by a two steps approach: nonlinear on the whole motor domain and hysteretic on the rotor one, the two solutions are coupled by boundary conditions. The main aim of the work is to evaluate the effect of the hysteresis of the hard magnetic material (Vicalloy 52KF7) on the magnetic field distribution, on the hysteresis losses and to provide comparison with experiments.

A new general typology of optimization algorithm inspired to classical swarm intelligence, the Continuous Flock-Of-Starlings Optimization (CFSO), is used to face the inverse problem of modeling magnetic materials. It is obtained by translating the numerical swarm/flock-based algorithms into differential equations in the time domain and employing analytical closed-forms written in the continuum. The modeling of magnetic hysteresis is very important for the development of magnetic materials and the accurate design of electrical machines. Recently several hysteresis vector models have been proposed and discussed; one of them is the Vector Hysteron Model (VHM) which is a natural extension of the Preisach theory to the vector case. In this work we present a CFSO based approach for the identification of VHM in order to reproduce scalar and rotational hysteresis loops. Experimental validations are made for both NOG (Not oriented grain) and OG (Oriented grain) steels.

A new hysteresis operator for the simulation of Goss-textured ferromagnets is here defined. The operator is derived from the classic Stoner–Wohlfarth model, where the anisotropy energy is assumed to be cubic instead of uniaxial, in order to reproduce the magnetic behavior of Goss textured ferromagnetic materials, such as grain-oriented Fe–Si alloys, Ni–Fe alloys, and Ni–Co alloys. A vector hysteresis model based on a single hysteresis operator is then implemented and used for the prediction of the rotational magnetizations that have been measured in a sample of grain-oriented electrical steel. This is especially promising for FEM based calculations, where the magnetization state in each point must be recalculated at each time step. Finally, the computed loops, as well as the magnetic losses, are compared to the measured data.

The modeling of dynamic hysteresis loops of soft magnetic materials is carried out using extended hyperbolic model. The extension is based on pure phenomenological approach and consists in elliptical component addition. This component features rounded shapes of dynamic hysteresis loops at low intensities of magnetization and it needs two parameters only. Fitting parameters for each loop are searched individually, and their dependences are then approximated by rational functions. The final model operates with approximated parameters. Proposed model was tested for the material FeNi47Cu5 at sinusoidal excitation at frequency 50 Hz.

We present a variable variance Preisach model that fully accounts for the different magnetization processes of a multilayer structure with perpendicular magnetic anisotropy by adjusting the evoluti ...

The Preisach model is a classical method for describing nonlinear behavior in hysteretic systems. According to this model, a hysteretic system contains a collection of simple bistable units which are characterized by an internal field and a coercive field. This set of bistable units exhibits a statistical distribution that depends on these fields as parameters. Thus, nonlinear response depends on the specific distribution function associated with the material. This model is satisfactorily used in this work to describe the temperature-dependent ferroelectric response in PZT- and KNN-based piezoceramics. A distribution function expanded in Maclaurin series considering only the first terms in the internal field and the coercive field is proposed. Changes in coefficient relations of a single distribution function allow us to explain the complex temperature dependence of hard piezoceramic behavior. A similar analysis based on the same form of the distribution function shows that the KNL–NTS properties soften around its orthorhombic to tetragonal phase transition.

In the present paper, the Preisach model of hysteresis is applied to model cyclic behavior of elasto-plastic material. Rate of loading and viscous effects will not be considered. The problem of axial loading of rectangular cross-section and cyclic bending of rectangular tube (box) will be studied in details. Hysteretic stress-strain loop for prescribed history of stress change is plotted for material modeled by series connection of three unite element. Also moment-curvature hysteretic loop is obtained for a prescribed curvature change of rectangular tube (box). All obtained results clearly show advantages of the Preisach model for describing cyclic behavior of elasto-plastic material.

In this paper, the identification of soft magnetic B - H characteristics when using the single measured hysteresis loop and fitting the discrete dynamic Preisach (DDP) model is addressed. The magnetic measurements with primary and secondary windings are performed to obtain the magnetostatic system response. The constrained least-squares estimation of the Preisach density function yields the global solution even for limited hysteresis data. The uncertainties detected during the measurement and computation of B and H values are discussed.

This paper deals with the computation of hysteresis torque in electric machines by means of the hysteresis Preisach model in finite element methods. In most cases, core loss is divided into hysteresis loss and eddy current loss. However, this component experiences mostly hysteresis loss at low speed. This hysteresis loss acts on the braking torque with cogging in the permanent magnet motor. In order to analyze the hysteresis torque, the Preisach hysteresis model is applied to the post-processor using the finite element method. In this method, computation errors can occur more than with the existing analysis method, but this method can compute hysteresis torque without complex nonlinear analysis. The hysteresis torque that is bearing friction is compared with test results. Both simulations and experiments are performed to verify the validity of the proposed method.

This paper introduces a differential approach to model scalar hysteresis based on the Preisach theory. This model can generate hysteresis trajectories for both symmetrical and asymmetrical minor loops and keep the memory of a material in a proper manner. It can easily be inverted, it has a simple algorithm with suitable computational speed, and is not memory consuming. Also, the obtained results of the model are in very good agreement with measurements.

This paper deals with the modeling of vector fields that exhibit hysteresis. A general class of models of vector magnetizations with hysteresis that form a natural extension of the Classical Scalar Preisach Model is defined. Although the modeling was done for the 2-d case, the same theory can be extended to the 3-d case as well. After reviewing some general properties of conservative fields, the specific case of unit magnitude vector fields is discussed. The paper focuses on discussing the properties of a general vector hysteresis operator (hysteron). The mathematical approach followed here can be applied not only to the magnetic hysteresis, but also to any hysteresis process. Some examples of vector hysterons, deduced from the general definition, are presented and their properties analyzed.

It is necessary to describe the hysteresis characteristics of magnetic material precisely for the analysis or design of system with ferromagnetic materials. Although Preisach model is regarded as the most accurate method to describe the hysteresis characteristics, it is not widely applied to the real systems because of some difficulties. The conventional Preisach model shows the numerical instabilities during the iterative computations because the density distribution obtained from the sets of M-H curves are strongly localized. To remove such numerical instabilities, M-B instead of M-H is adopted as an implementation variable in normal Preisach modeling. The two dimensional computations with hysteresis characteristics by using normal Preisach modeling are tested and the result showed that the modeling by using M-B variables showed better stabilities than M-H variables.

Hysteresis effects hinder the accurate control of electromagnetic actuators and require auxiliary sensors for properly determining the hysteretic system state. The physics-based Jiles-Atherton and the phenomenological Preisach hysteresis models provide powerful means to describe the magnetic hysteresis and its inverse. In this paper, we consider both hysteresis models in the scalar form from the control points of view, with a primary objective of the sensorless inverse feed-forward control. The identification complexity, the runtime, and the space efficiency of the control-oriented implementation are analyzed and compared for both modeling approaches. Their control performance for an inverse hysteresis compensation is experimentally evaluated on a specific force-controlled electromagnet system.