Search

With the increase in power electronic equipment in power system, the excitation of ferromagnetic materials often involves a large number of harmonics. Therefore, it is necessary to construct an accurate dynamic hysteresis model to adapt to this complicated operating state of electrical equipment. In this paper, a Hybrid Dynamic Hysteresis Model (HDHM), which can effectively characterize the harmonic excitation of materials is studied based on the Preisach model and Stacked Auto-Encoder (SAE) model. The static part of this model takes the form of the inverse Preisach model. And the Multiple Dynamic Hysteresis Model Set (MDHMS) is constructed by multiple dynamic models of eddy currents and excess characteristics of the ferromagnetic materials. The dynamic part of the HDHM takes the form of the model structure combining the Stacked Auto-encoder and the MDHMS. The calculation results of the hysteresis loop and ferromagnetic loss in the harmonic condition of silicon steel sheet proves the validity of this model. Moreover, compared with the conventional dynamic hysteresis model, the HDHM has better accuracy and generalization ability. [ABSTRACT FROM AUTHOR]

This paper proposes an advanced approach to construct static hysteresis loop of Grain-Oriented (GO) electrical steels for dynamic modeling and energy loss analysis. The proposed approach is in line with the magnetic hysteresis and phenomenological concepts of rate-dependent and rate-independent energy loss components of ferromagnetic materials under time-varying magnetic fields. The proposed method can predominantly describe energy loss mechanism and magnetization processes of the material. Accuracy of this technique was validated on Epstein size laminations of 3% GO silicon steels. The results explicitly confirmed the effectiveness of the proposed method in dynamic hysteresis modeling of GO electrical steels at magnetizing frequencies up to 1 kHz and peak flux densities up to 1.7 T. [ABSTRACT FROM AUTHOR]

Transformers, reactors and other electrical equipment often work under harmonics and DC-bias working conditions. It is necessary to quickly and accurately simulate the hysteresis characteristics of soft magnetic materials under various excitation conditions in order to achieve accurate calculations of core loss and the optimal design of electrical equipment. Based on Preisach hysteresis model, a parameter identification method for asymmetric hysteresis loop simulation is designed and applied to the simulation of hysteresis characteristics under bias conditions of oriented silicon steel sheets. In this paper, the limiting hysteresis loops of oriented silicon steel sheets are obtained through experiments under different working conditions. The first-order reversal curves(FORCs) with asymmetric characteristics is generated numerically, and then the Everett function is established under different DC bias conditions. The hysteresis characteristics of the oriented silicon steel sheets under harmonics and DC bias are simulated by improving FORCs identification method of the Preisach model. By comparing the results of simulation and experiment, the effectiveness of the proposed method is verified, so as to provide an important reference for material production and application. [ABSTRACT FROM AUTHOR]

Based on the consideration of the magnetic domain motion under different magnetization levels, an improved J-A model with variable parameters is proposed to solve the problem of significant errors in the process of calculating the inner symmetric small loops. The proposed method introduces a variable scale parameter v(B) to correct the irreversible magnetization component of the J-A model. Meanwhile, based on the magnetic domain theory, a method with variable pinning parameter k(B) and a variable domain wall bending parameter c(B) is proposed. By comparing the measured data of B30P105 Grain-Oriented (GO) silicon steel, the calculation error for each magnetization level of the model is within 7%, which means that the global hysteresis properties of GO silicon steel can be well reproduced. [ABSTRACT FROM AUTHOR]

Aiming at the weak capacity of the parameter identification methods of Jiles–Atherton (J–A) hysteresis model, such as slow convergence speed and low convergence accuracy, an improved sparrow search algorithm (IM-SSA) is proposed based on mutation crossover operator and T-distribution perturbation strategy in this paper to improve the convergence speed and accuracy of parameter identification method. Firstly, the initial population of the sparrow search algorithm is enriched by Tent chaotic sequence, which expand the search area. Then, the adaptive crossover and mutation operator is introduced into the finders population to enrich the diversity of the finders population and balance the global and local search ability of the algorithm. Secondly, the T-distribution perturbation or differential mutation is used to perturb the population after each iteration according to the individual characteristics, which can avoid the population singularity in the later stage of the algorithm and enhance the ability of jump out of the local optimal value of the algorithm. Finally, the proposed parameter identification method is used to identify the parameters of the J–A hysteresis model, which are used to simulate the magnetic properties of Non-oriented silicon steel sheets with different magnetic induction intensity. The calculation result is compared with the experiment ones. The results proved that the proposed method has faster convergence speed and higher convergence accuracy. [ABSTRACT FROM AUTHOR]

This article presents an improved algorithm for identification of the excess loss statistical parameter to get more accurate prediction of multiple harmonic magnetic hysteresis and loss properties of grain-oriented silicon steel sheets. Magnetic hysteresis characteristics of a specimen are measured on a magnetic measurement platform. Static hysteresis property can be simulated accurately by the Preisach model. The excess loss field expression under multiple harmonic magnetizations is constructed based on an extraction algorithm for the statistical parameters of excess loss. According to the equivalence of loss separation and field separation, a new dynamic model is established. In the case of different multiple harmonic magnetizations, the magnetic hysteresis characteristics obtained by predictions are compared with the test results. Also, the influences of peaked flux density, harmonic order, and harmonic content upon the total iron loss are investigated. [ABSTRACT FROM AUTHOR]

This article presents an improved dynamic hysteresis model to predict magnetic hysteresis properties under high-frequency sinusoidal excitations. A new expression of magnetic field strength related to classical loss is derived and proposed to consider the effect of skin effect on the iron loss. The permeability related to statistical parameter is presented to establish the relationship between classical loss and excess loss. The introduction of shape factor provides a possibility for accurate prediction of dynamic loops at high frequency over a broad induction range. The accuracy of the proposed dynamic hysteresis model is verified by comparing the predicted results with the measured ones. In addition, the variation of loss components with frequency and peaked induction is analyzed. [ABSTRACT FROM AUTHOR]

The high-frequency iron losses caused by sinusoidal flux density variations with frequencies ranging from 2.5 to 40 kHz, amplitudes from 1 to 70 mT, and dc-biased magnetic inductions from 0 to 1.62 T are measured with the dual-transformer system. Then, in this article, a simple frequency-domain model is proposed based on the linear fitting and two-dimensional interpolation methods for engineering applications. In addition, another two frequency-domain models, respectively, considering and neglecting the excess losses are investigated and compared for the high-frequency iron-loss modeling, which only need low-frequency parameters and contain the physical interpretation to the variation of high-frequency iron-loss coefficients with the frequency, ac flux density amplitude, and dc-biased magnetic induction. The iron losses generated by the unipolar and bipolar pulsewidth modulation (PWM) voltages with different switching frequencies and modulation factors are measured to testify the three models. It is shown that the three models in this article are more accurate than the previously proposed one for calculating the PWM-induced iron loss by considering the variation of model parameters with the dc-biased magnetic induction and ac flux density amplitude, especially when silicon steel sheets reach the saturation. [ABSTRACT FROM AUTHOR]

Accurate simulation of the hysteresis loop is challeng-ing, especially using manufacturer data. Traditional parameter extraction methods (e.g., using optimization algorithm and solving transcendental equation) can extract the static Jiles-Atherton (JA) hysteresis model parameters under an arbitrary condition, but it requires fitting parameters because the model parameters vary with flux density. To reduce the dependence on measurement data, this paper proposes a simple but effective parameter extraction method. Firstly, an identification procedure of minor loop is presented using only static B-P loss curves by investigating the influence of model parameters on hysteresis loop, where the average root-mean-square error of the hysteresis loop is decreased by 4. To estimate the dynamic loss coefficients under DC bias, a calculation method based on the Statistical Theory of Losses (STL) is established by investigating the law of influence of DC bias on hysteresis loss and dynamic loss. The effectiveness of the proposed method is verified. [ABSTRACT FROM AUTHOR]

In the area of automotive propulsion, electric motors experience core losses due to the presence of higher harmonic frequencies, particularly those arising from pulse width modulation switching. Consequently, it is required to establish a practical model capable of characterizing the hysteresis loops in electrical steel when subjected to harmonic excitations. Nonetheless, existing dynamic models may be inappropriate for real-world applications due to their inherent complexity and their tendency to neglect the influence of minor loops arising from harmonics. In the present work, the minor and major hysteresis curves of non-oriented silicon steel sheets are measured under variable frequency excitation containing harmonic components. To reproduce the asymmetrical minor hysteresis loops, a modified arctangent model is employed. The evaluation of the accuracy of this hysteresis model is conducted by comparing the fitted results of static and dynamic hysteresis loops against experimental data, both with and without harmonic excitation. [ABSTRACT FROM AUTHOR]

A new algorithm for numerical identification of the static Preisach hysteresis model is proposed for more accurate estimation of dc-biasing hysteresis curves and hysteresis loss of the grain-oriented silicon steel sheet. Based on the experimental asymmetric major hysteresis loop under dc-biased magnetization, two sets of first-order reversal curves corresponding to ascending and descending branches, respectively, are numerically generated for construction of the Everett function. According to the equivalent field separation technique, a dynamic hysteresis model is established by parameter extraction of excess loss, and then used for simulation of dc-biasing dynamic hysteretic behaviors. The consistency between the simulated results and the measured ones demonstrates the effectiveness of the proposed method. The effect of dc bias on iron loss is analyzed as well. [ABSTRACT FROM AUTHOR]

Samples from FeSi4 powder were fabricated with a low power selective laser melting (SLM) system using a laser re-melting strategy. The sample material was characterized through magnetic measurements. The study showed excellent DC magnetic properties, comparable to commercial and other 3D printed soft ferromagnetic materials from the literature at low (1 T) magnetization. Empirical total core losses were segregated into hysteresis, eddy and excessive losses via the subtraction of finite element method (FEM) simulated eddy current losses and hysteresis losses measured at quasi-static conditions. Hysteresis losses were found to decrease from 3.65 to 0.95 W/kg (1 T, 50 Hz) after the annealing. Both empirical and FEM results confirm considerable eddy currents generated in the printed bulk toroidal sample, which increase dramatically at high material saturation after annealing. These losses could potentially be reduced by using partitioned material internal structure realized by printed airgaps. Similarly, with regard to the samples characterized in this study, the substantially increased core losses induced by material oversaturation due to reduced filling factor may present a challenge in realizing 3D printed electrical machines with comparable performance to established 2D laminated designs. [ABSTRACT FROM AUTHOR]

This article presents a modified Jiles–Atherton hysteresis model for a weakly anisotropic non-oriented silicon steel sheet. In a toroidal inductor, the magnetic flux density can point toward any direction compared to the sheet orientation, and the hysteresis model should take this into account. We identify the model parameters independently for unidirectional alternating B(H)-characteristics in seven different directions. Then, we construct an anisotropic hysteresis model, where the model parameters can depend on the magnitude and direction of the applied magnetic flux density. We demonstrate that the parameters identified in the rolling and transverse directions of the silicon steel sheet (M400-50A) are sufficient to describe the hysteresis losses in other directions. [ABSTRACT FROM AUTHOR]

• In this paper, we propose a new parameter identification method of inverted Preisach model, which uses the measured quasi-static concentric hysteresis loops to simulate the static DC hysteresis behavior of grain-oriented silicon steel sheets. • Then, the dynamic magnetic field intensity related to excess loss is improved by considering the nonlinear relationship between statistical parameter of excess loss V 0 and AC peaked magnetic flux density B acm , DC magnetic field intensity H dc and frequency f. • Finally, a dynamic hysteresis model in the form of field separation is proposed to predict the asymmetric hysteresis curve under AC-DC hybrid magnetization. The simulation hysteresis curve and loss under different AC-DC hybrid magnetization are compared with the measured ones, which verifies the accuracy and effectiveness of this method. Firstly, a new method for parameter identification of inverted Preisach model is proposed to simulate static DC-biasing hysteresis behavior of the grain-oriented (GO) silicon steel sheet by using the measured quasi-static concentric hysteresis loops under DC-biasing magnetization. Then, the dynamic magnetic field intensity related to excess loss is improved by considering the nonlinear relationship between the statistical parameter V 0 and the AC peaked magnetic flux density, DC magnetic field intensity as well as frequency. Finally, a dynamic hysteresis model in form of field separation is presented to predict asymmetric hysteresis curves under multi-harmonic and DC-biasing hybrid magnetization. The simulated hysteresis curves as well as losses under different AC-DC hybrid magnetizations are compared with the measured ones, which verifies the accuracy and effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

To evaluate the iron losses of motors and three-phase transformers, the rotational iron loss should be considered. A simple numerical calculation method of the rotational iron losses under rotational flux with high flux density and different axis ratios is proposed in this paper. First, it is shown that the method of decomposing the rotational flux into the directions of the major and minor axes of the rotational flux is effective in calculating the rotational iron losses of the non-oriented and grain-oriented electrical steel sheets in low magnetization region. Then, the simple iron loss calculation method is improved to consider the decrease of rotational hysteresis and anomalous eddy current losses in high magnetization region under circular rotational flux and verified by comparing with measurement results. Furthermore, it is improved to be applicable to rotational iron loss calculation under rotational flux with different axis ratios and verified by comparing with measurement results. [ABSTRACT FROM AUTHOR]

Non oriented silicon steels are widely used within rotating electrical machines and are assumed to have no anisotropy. There exists a need to detect the anisotropic magnetic properties and to evaluate the local changes in magnetic material properties due to manufacturing cutting processes. In this paper, the so called moving magnet hyteresis comparator is applied to non destructively detect directional variations in coercive force in a variety of local regions of rotor and stator laminations of two materials commonly used to construct induction motors cores. [ABSTRACT FROM AUTHOR]

Magnetic materials exhibit varied hysteresis behaviour at different operating conditions. The exact determination of magnetic characteristics requires an accurate measurement setup. A low cost high performance digital hysteresis loop tracer has been built to measure magnetic characteristics of ferromagnetic materials under controlled sinusoidal and non-sinusoidal flux density waveforms. A digital feedback program is developed in LabVIEW to trace hysteresis characteristics using measured voltages and currents. In this paper, magnetic characteristics and losses of Grain-oriented (GO) silicon steel and ferrite materials are obtained at different frequencies. Losses determined by calculating the area under the hysteresis loop are compared with measurements from a power analyzer. The proposed experimental setup can be used to characterize different materials at various frequencies. [ABSTRACT FROM AUTHOR]

Amorphous alloy is increasingly widely used in the iron core of power transformer due to its excellent low loss performance. However, its potential harm to the power system is not fully studied during the electromagnetic transients of the transformer. This study develops a simulation model to analyze the effect of transformer iron core materials on ferroresonance. The model is based on the transformer π equivalent circuit. The flux linkage–current (ψ–i) Jiles–Atherton reactor is developed in an Electromagnetic Transients Program-Alternative Transients Program and is used to represent the magnetizing branches of the transformer model. Two ferroresonance cases are studied to compare the performance of grain-oriented Si-steel and amorphous alloy cores. The ferroresonance overvoltage and overcurrent are discussed under different system parameters. Results show that amorphous alloy transformer generates higher voltage and current than those of grain-oriented Si-steel transformer and significantly harms the power system safety. [ABSTRACT FROM AUTHOR]

Bertotti’s model for excess eddy-current (EC) loss is combined with the dynamic hysteresis model represented by a Cauer circuit and the play model. The excess EC field of the Cauer circuit is represented by nonlinear resistors. A formulation of excess EC field based on nonlinear current conduction is developed for the finite-element EC analysis, which is applied to the physical Cauer circuit. The proposed models improve the ac iron-loss evaluation under sinusoidal excitation of frequencies up to 20 kHz and achieve an accurate $B$ – $H$ loop representation under pulse-width modulation excitations. [ABSTRACT FROM AUTHOR]

Two kinds of 0.23 mm-thick high-silicon steel sheets with strong η-fiber texture and Goss texture were produced by rolling methods. Their final microstructures, textures and magnetic properties were analyzed by scanning electron microscope (SEM), transmission electron microscope (TEM), energy-dispersive spectroscopy (EDS), X-ray diffractometer (XRD), electron backscattered diffraction (EBSD) and classical loss separation. The results showed that the core loss of strong η-fiber-oriented high-silicon steel was lower than that of grain-oriented high-silicon steel at frequencies ranging from 40 Hz to 20 kHz, and their differences in core loss were more obvious at 400 Hz and higher frequencies. The hysteresis losses and anomalous losses of the strong η-fiber-oriented high-silicon steel were lower than that of grain-oriented high-silicon steel at frequencies ranging from 40 Hz to 1000 Hz, and the losses were closely related to final cleanness and grain sizes. A few stable remained nitride precipitates increased the hysteresis loss of the grain-oriented high-silicon steel. The effect of decreasing grain sizes on decreasing core losses at high frequencies was significant, and the strong η-fiber-oriented high-silicon steel was more suitable for high frequency applications because of smaller grain sizes compared to the grain-oriented high-silicon steel. [ABSTRACT FROM AUTHOR]

Deals with a study which detailed Epstein-frame loss measurements on 3.2 percent Si-Fe non-oriented strips cut along and transverse to the rolling direction. Indication of the dependence of measured hysteresis and excess losses on peak induction; Law that is assessed as a general property of non-oriented silicon steels and many other soft materials; Analysis of the crystallographic texture.

This paper presents the finite element level validation of the anisotropic Jiles–Atherton hysteresis model. Numerical analysis of a round rotational single sheet tester is performed using the 2D finite element method. Anisotropic extension of the Jiles–Atherton hysteresis model is coupled with the 2D finite element method. The finite element simulations are performed for the cases when the magnetic field alternates and rotates in the lamination plane. The simulated results for alternating and rotational flux density excitations agree with the measured data. The measured data used in this paper corresponds to the M400-50A nonoriented silicon steel. • Finite element level validation of an anisotropic Jiles–Atherton hysteresis model for NO FeSi electrical steel sheet. • Inclusion of the isotropic and anisotropic Jiles–Atherton hysteresis model in the 2D finite element method. • Finite element analysis of a round rotational single sheet tester. • Comparison of the finite element analysis results with the measurement data. • The anisotropic Jiles–Atherton hysteresis model predicts alternating and rotational field strength loci better than the isotropic Jiles–Atherton hysteresis model. [ABSTRACT FROM AUTHOR]

A specially developed setup for precise measurement of magnetic hysteresis and Barkhausen noise is presented in this paper. A novelty of the setup consists in a unique combination of two main features: 1) an accurate local determination of the magnetic field and 2) an improved feedback control of the magnetization process. First, the magnetic field is measured by two Hall sensors at different distances above the sample. The sample field is determined by a linear extrapolation of these measured profiles of the tangential fields to the sample surface. Second, a digital feedback loop for precise control of the ac magnetization process is proposed. The feedback algorithm combines two methods of magnetizing signal adjustment: linear corrections of the magnetizing voltage amplitude and phase. The presented system is able to adjust the waveform of the magnetic induction or field to the prescribed sinusoidal or triangular shape. This provides stable and physically accurate results, which are independent of a specific experimental configuration. [ABSTRACT FROM AUTHOR]

This paper proposed a temperature-dependent iron loss model and corresponding dynamic hysteresis model, where temperature coefficient k is introduced to consider the thermal effect on eddy-current loss. The iron loss model is validated by massive experimental measurement of test samples, 1174 combinations of various temperatures, magnetic inductions, and frequencies for nonoriented silicon steel specimen. The relative error of the model is $\sim 11$ % in a wide range of 50–400 Hz, 26 °C–200 °C, and 0–2 T. The proposed method can be applicable to other types of magnetic materials as long as whose resistivity rate exhibits approximately linear thermal dependence within a temperature range of 26 °C–200 °C. [ABSTRACT FROM AUTHOR]

This paper presents a vector hysteresis model based on micromagnetic theory. In this model, a magnetization state of a magnetic material is described by a collection of single-domain particles, and magnetic reversal processes due to domain-wall motions are treated approximately as a magnetization flip. The present model is applied to calculation of hysteresis properties of grain-oriented silicon steel. The simulation results show that the anisotropic hysteresis properties and iron loss can be reproduced accurately by the present model. [ABSTRACT FROM AUTHOR]

A newly developed measurement system was comprehensively tested for the industrially attractive case of an open magnetic circuit. Series of industrial electrical steels were magnetized by a single yoke through a gap of several millimeters. According to standards, the magnetic induction waveform was adjusted to a 50-Hz sine curve using a digital feedback procedure. The magnetic surface fields above the sample were measured directly by a vertically mounted array of three Hall sensors. The actual magnetic field was determined by a linear extrapolation of the measured field profile to the sample face. It was experimentally shown that control of the induction waveform and simultaneous direct determination of the sample field make the hysteresis loop measurements independent of the yoke-sample gap. In addition, the obtained physically correct data show good linear correlations with the corresponding standard values measured by a single sheet tester. These outcomes are important for revision of the principles of industrial testing and further development of the measurement standards. [ABSTRACT FROM AUTHOR]

This paper presents measured local vector magnetic properties in a transformer type model core made of a laser-scratched grain-oriented electric steel sheet by using a vector-hysteresis (V-H) sensor. The V-H sensor consists of B-needle probes for measurement of the magnetic flux density vector B and double H-coil for measurement of the field strength vector H. The distance between the B-needle probes was shortened to be 2.5 mm and a 2 mm \times 2 mm-sized double H-coil was mounted on the sensor head to realize higher resolution. The measurement accuracy of the B-needle probes was confirmed with a spatial probe, which can change the needle distance from 2 mm to 20 mm. The results show that the detailed local two-dimensional vector magnetic properties depending on laser-scratches are measurable with the developed new sensor. [ABSTRACT FROM PUBLISHER]

Electrical steels with lower thickness become more and more important to realize electrical machines with high nominal frequency due to high number of the poles and to provide higher power at a given volume of the electrical machine. For application at higher frequencies the dynamic magnetization processes have to be analyzed. In the paper the experimental data for frequency dependence of the magnetization curves, the coercive force, the permeability, and of the magnetic losses for nonoriented electrical steels with thicknesses in the range of 0.10 mm up to 0.50 mm will be reported. For thin electrical steels a different character of the dynamic magnetization behavior at increasing frequency of the applied external field compared to thicker materials is observed. This is attributed to differences in the number of moving walls. [ABSTRACT FROM PUBLISHER]

The influence of the tile angle of the [001] out of crystal surface \beta on iron loss improvement of 3 % Si steel single crystals was investigated. This iron loss improvement was caused by tensile stress effect of TiN coating and domain refinement. When \beta angle was less than 3 degrees, both eddy current loss and hysteresis loss decrease. Extremely low iron loss was obtained, when \beta angle equal to about 2 degrees. On the other hand, when \beta angle is more than 3 degrees, the hysteresis loss increased though the eddy current loss decreased by TiN coating. As a result, change in iron loss was small after TiN coating and domain refining. Therefore, it was clarified that the iron loss improving methods, such as domain refining and ultra-high tension coating, were effective especially in grain oriented electrical steel whose \beta angle is less than 3 degrees. [ABSTRACT FROM PUBLISHER]

A phenomenological vector hysteresis model is developed to represent dynamic and weakly anisotropic vector hysteretic properties of nonoriented silicon steel sheets. The anisotropic vector hysteresis is represented by the multiplication of an anisotropy matrix and an isotropic vector play model. An eddy-current field vector given by classical eddy-current theory and an anomaly factor is added to the vector hysteresis model. The anomaly factor is determined to model the decrease in anomalous eddy-current loss under conditions of large rotational magnetic flux. The alternating and rotational properties simulated by the proposed model reconstruct the measured magnetic properties of nonoriented silicon steel sheets. [ABSTRACT FROM PUBLISHER]

This paper presents a generalized Chua-type vector hysteresis model to describe both the static and dynamic vector magnetic properties of electrical steel sheets. The proposed model takes into account all significant harmonic components of the measured H-waveforms, thus it provides precise prediction of H-waveforms even under highly saturated magnetic flux densities under alternating, rotating, and distorted magnetic fields conditions. The validity of the proposed vector hysteresis model was investigated by comparison to experimental results under various magnetic field conditions for both the non-oriented and grain-oriented silicon steel sheets. [ABSTRACT FROM PUBLISHER]

The magnetic modeling of Si-Fe magnetic steels is presented in this paper. The modeling is based on a class of vector hysteresis operators recently introduced. The vector approach works without the additional manipulations and the corrections of the scalar case. The distribution of the probability function of the vector hysteresis operators is identified by a suitable set of magnetic measurements. Experimental verifications about the prediction of the model of some magnetization processes are presented. [ABSTRACT FROM AUTHOR]

A simple anisotropic vector hysteresis model is developed to represent 2D weakly anisotropic vector hysteretic property. An isotropic vector play model is identified from azimuthally averaged vector property of anisotropic material. An anisotropy matrix is multiplied to the isotropic vector play model to represent anisotropy. Simulations for alternating and rotational flux conditions show that the anisotropy matrix improves the representation of vector hysteretic properties for a non-oriented silicon steel sheet. [ABSTRACT FROM AUTHOR]

Abstract: The paper is aimed at modelling dynamic hysteresis loops of high silicon steel. Hysteresis loops are described with the modified Jiles–Atherton approach. The dynamic effects due to eddy currents are taken into account by the introduction of components of effective field related to loss components in Bertotti''s model. A satisfactory agreement between the measured and the modelled dynamic hysteresis loops as well as derived quantities is obtained for those values of peak flux density and frequency, which are of interest from industrial point of view. [Copyright &y& Elsevier]

In this work the potential of the Barkhausen noise technique for testing of the magnetic properties of electrical steels was studied. Different grades of nonoriented and grain oriented steels were tested in the quasi.static magnetization regime. A vertical array of three Hall sensors was used to control the sample field. Barkhausen noise was detected locally by a pancake coil with Fe-Si laminated core. A new parameter, Barkhausen noise coercivity, was introduced. Its linear correlation with the important magnetic parameters, the real coercive force and the hysteresis loss, was established. The applicability of the Barkhausen noise method for industrial control of the steel quality was discussed. [ABSTRACT FROM AUTHOR]

We present Barkhausen noise and magnetic measurements on two fully processed, nonoriented electrical steels which had been coldrolled to thickness reductions of up to 60%. Both coercive field H and hysteresis loss Wh show an almost linear increase with thickness reduction up to the highest deformations. These changes are almost fully reversed after vacuum annealing for 2 hat 760° C. The hysteresis loss can be conveniently subdivided into high and low induction components as suggested by recent modelling. Electron back-scatter diffraction (EBSD) shows no texture change during initial phases of cold-rolling. Barkhausen noise measurements were obtained on both cold-rolled and annealed samples. The undeformed material shows a Barkhausen signature consisting of two small peaks which coalesce into one peak upon plastic deformation and thereafter grow steadily. Annealing the material brings back the two-peaked signature. These results are discussed and hypotheses are presented for the behavior of the Barkhausen noise. [ABSTRACT FROM AUTHOR]

The objective of the presented work was to introduce the principles of direct field control into magnetic measurements. Different grades of nonoriented and grain-oriented steels were tested in dc magnetization regime. A vertical array of three Hall sensors was used to control the sample field. With small gradients of the sample surface field our results showed comparable measurement errors with the single sheet tester. Measurement of the hysteresis loss and the coercive force was mostly independent of the field determination method. However, for accurate estimation of the magnetic induction parameters the sample field should be determined directly. No unique dependence was found between the measured dc and 50 Hz Epstein/single sheet tester parameters except the remanent induction of the nonoriented steels. [ABSTRACT FROM AUTHOR]

Microstructural deterioration near the cut line and presence of residual stresses both affect the magnetic properties of cut parts. In this paper, the differences between microstructural deterioration resulting from mechanical and laser cutting as well as the sample size effects observed upon hysteresis will be discussed. It will be shown that the underlying mechanism for changes in magnetic properties due to mechanical cutting is distinct from that of laser cutting. [ABSTRACT FROM AUTHOR]

• The HIHM has the better structure and higher precision than traditional models. • The magnetization state vector is used to characterize the specific magnetization of materials. • The modeling of HIHM can reduce the requirement of hysteresis data. • The HIHM can overcome this unreasonableness in the modeling of Preisach. • To the parameter identification of the J-A model, the training of HIHM taken less time. The hysteresis modeling of ferromagnetic materials in electrical equipment is one of the basic theoretical studies in the field of electrical engineering. Long training time and poor accuracy are the main challenges of the traditional hysteresis models. In this paper, a Hybrid Intelligent Hysteresis Model (HIHM) is proposed by combining the hysteresis operator space theory and Deep Belief Networks-Deep Neural Network (DBN-DNN) algorithm. The Preisach Fusion Operator (PFO) is constructed by fusing multiple traditional Preisach operators with coefficients satisfying the Gaussian distribution. And multiple PFOs are used to construct an operator space to create the high-dimensional operator data. By the operator space, the nonlinear hysteresis relationship in the hysteresis data is transformed into a nonlinear mapping between the operator data and the output of the model. The DBN-DNN model is used to characterize this nonlinear mapping. The structure of the HIHM is determined by taking the output of the operator space as the input of the DBN model. The generation of first-order reversal curve proves that the model has certain practicality. In addition, the validity and generalization of this model is verified through the simulation with experimental data of non-orientation (NO) silicon steel B35A210 at quasi-static frequency. [ABSTRACT FROM AUTHOR]

This article discusses saturation properties of two-dimensional isotropic vector hysteresis models using geometrically vectorized stop and play hysterons. The vector stop and play hysterons are modified to obtain natural saturation properties. The modified hysterons improve rotational properties of vector stop and play models under a saturated condition. [ABSTRACT FROM AUTHOR]

Abstract: The capabilities of stop and play models to represent minor hysteresis loops of a silicon steel sheet are compared. Identification of stop and play models using only symmetric BH loops results in an inaccurate representation of minor loops, whereas identification using only first-order reversal curves from negative saturation yields inaccurate symmetric BH loops. A least-squares identification method, using both symmetric loops and first-order reversal curves from saturation, enables the play model to accurately represent minor loops including their hysteresis losses. [Copyright &y& Elsevier]

Abstract: The effects of laser irradiation on iron loss reduction for Fe–3%Si grain-oriented silicon steel sheet were investigated. The local tensile residual stress states near the laser irradiated cavity lines were observed by using the new X-ray stress measurement method for a single crystal. Although the higher laser power induced the larger tensile residual stresses, the minimum iron loss was obtained at the medium tensile residual stress conditions of about 100–200 MPa. The increase of Vickers hardness was observed with increasing laser power, which was the mark of the plastic deformations induced by the laser irradiation. The tensile residual stress reduces eddy current loss and the plastic deformation increases hysteresis loss of the material. The total iron loss is determined by the balance of these two effects of laser irradiation. [Copyright &y& Elsevier]

Presents a study that computed the harmonic eddy currents loss and the hysteresis loss of a piece of silicon steel sheet of an interior permanent magnet (IPM) using the three-dimensional finite-element method. Background on the use of IPM motors; Analysis the effects of the phase difference between the induced voltage and the coil current on the torque; Results and implications.

Proposes a combination of stop and play models for the representation of the magnetic characteristics of silicon steel sheet. Comparison of the ability of the stop and play models to represent hysteretic relations from magnetic flux density to hysteretic output of magnetic field; Application of the stop and play models.

This paper presents a numerical modeling of vector (two-dimensional) magnetic properties considering hysteresis of silicon steel sheets. We define the magnetic reluctivity tensor newly and calculate it from the measurement data obtained by two-dimensional magnetic measurement. Our new modelings, which are "E&S Model" and "E&S2 Model", can be introduced into a finite element formulation for magnetic field analysis and can get the distribution of the magnetic field strength H-vector and the magnetic flux density B-vector. [ABSTRACT FROM AUTHOR]

The increasing interest in magnetic measurements in machine laminations under rotating fields requires better interpretations for many unclear observations, which have been noticed and documented experimentally. One of these observations is the negative value of power, which is reported during the measurements of rotational core losses using the field metric method. This paper addresses the problem of negative power and gives a descriptive picture for the field behavior by presenting the experimental hysteresis loops. Measurements were carried out on a nonoriented silicon steel sample of M36G26. A novel design of magnetizing test fixture based on an electromagnetic Halbach array is used to perform these measurements. Results show that the negative value of power in one loss component is a result of method of analysis, while the negative value of total rotational power loss is a consequence of faulty measurements. [ABSTRACT FROM AUTHOR]