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With the rise of eco-friendly policies, advanced motor technologies are being developed to replace fossil fuel-based engines in the mobility industry. Axial flux motors, known for their ability to reduce size and increase output torque compared to radial flux motors, require different materials and manufacturing techniques. Specifically, the production of complex stator cores and segmented magnets presents significant challenges, often leading to higher costs. To address this issue, soft magnetic composite (SMC) materials, which offer greater design flexibility, are being explored for use in stator cores. However, soft magnetic composite materials exhibit lower permeability and saturation flux density compared to laminated silicon steel, resulting in reduced output torque and efficiency. This paper investigates the effects of stator geometry on axial flux motor performance and explores cladding core technology, which combines soft magnetic composite materials with silicon steel. By conducting finite element method (FEM) analysis to evaluate the output torque and efficiency based on the shape of the silicon steel within the cladding core, this study proposes an optimized cladding core design to enhance the efficiency and output torque of axial flux motors. [ABSTRACT FROM AUTHOR]

The magnetic properties of a 0.10 mm ultra-thin, grain-oriented (UTGO) silicon steel and an Fe-based amorphous (FBA) alloy under sinusoidal excitation were experimentally researched, and the magnetic field strength and iron loss of the two materials under different frequencies and magnetic densities were obtained. Based on the measured data, the magnetization and loss characteristics of the two materials were analyzed and compared. Furthermore, two Epstein square ring models of the same dimensions and different materials were designed, and the reliability of the models was verified. Then, the electromagnetic characteristics of the two Epstein square ring models at higher and lower frequencies were calculated using the finite element method, and the iron losses were obtained and compared. The results show that the FBA alloy has good application characteristics at low frequencies and low power, and the 0.10 mm UTGO silicon steel has good application characteristics at high frequencies and high power. This research provides important data, promoting the application of these two materials in new energy equipment. [ABSTRACT FROM AUTHOR]

This paper presents an analytical model for computing and designing a three-phase Amorphous Core Transformer (ACT) with a power rating of 3 kVA, 380/127 V. Based on the main parameters obtained from the analytical model, a Finite Element Method (FEM) was developed to simulate the electromagnetic parameters, such as electric currents, operating voltages, and losses. Finally, an ACT installation was carried out with the steel material of code 2605SA1. The simulation results were compared with the experimental measurements under no-load and full-load operating conditions. Furthermore, the no-load loss of ACT was also compared to that of traditional transformers using silicon steel material. The obtained results prove that the use of ACT can save energy in the fields of education, health services, and industries. [ABSTRACT FROM AUTHOR]

In this study, the evolutions of Cube and {115}<161> orientations of a cold-rolled ultra-thin non-oriented silicon steel were investigated using a combination of experimental investigation and the crystal plasticity finite element method (CPFEM). The results show that Cube orientations remain relatively stable when their initial deviation angles from the ideal Cube orientation are less than 12°, even after a 60% cold rolling reduction. However, larger deviations occur due to higher strain near grain boundaries. Furthermore, the {115}<161> orientations, with an initial deviation of ~18° from the ideal Cube orientation, become separated into different orientation regions during cold rolling. Some regions gradually approach the ideal Cube orientation as cold rolling progresses and reach ~12.5° deviation from the ideal Cube at a 40% reduction. This study demonstrates good agreement between simulation and experimental results, highlights the micro-deformation mechanisms during rolling, and offers insights for optimizing the ultra-thin strip rolling process. [ABSTRACT FROM AUTHOR]

In industry, the most frequently used motors are induction motors (IMs), reluctance motors, and permanent magnet synchronous machines (PMSMs). Nowadays because of higher efficiency with higher power density, PMSM attracts its uses in every field of application. Hence, a spoke shape interior PM-based synchronous motor (IPMSM) with distributed winding is considered to discuss in this paper. Also, there has always been a dispute between 2D and 3D analysis of electromagnetic parameters of machines. Therefore, this paper discusses the accuracy, advantages, and difficulty level of 2D and 3D FEM analysis of the IPM motor model by considering several electromagnetic with electromechanical parameters such as torque, flux linkage, eddy current loss, etc. The performance of five different core materials is also considered for comparison. These analyses are carried out by using ANSYS Maxwell software. Spoke shape IPMSM of 0.55 kW with 220 V, 50 Hz is considered for analysis. The 2D and 3D comparison results of parameters under magnetostatic and transient conditions are presented and verified with the results reported in the literature. 2D FEM analysis has given more value in case of torque, stator current, and magnetic flux density than 3D analysis where as 3D analysis is give good performance for flux linkage, back EMF, and eddy current losses. Significant percentage changes with respect to observed materials in the results of 2D and 3D cases are reported. Silicon Steel M36 suitability for stator and rotor core is also observed. This 2D and 3D FEM analysis clarifies accuracy prior to design motor. [ABSTRACT FROM AUTHOR]

To suppress low frequency vibration and noise generated by power transformer in residential area and achieve environment protection standards, a double-beam metamaterial is proposed, which is fabricated through periodically coupling silicon steel sheet and aluminum beams with Belleville quasi-zero stiffness spring (BQZSS). The double-beam metamaterial can be assembled with iron core of transformers as a whole to obtain the design of a low-noise transformer. Performing static analysis, the mechanical model of BQZSS is established and the relationship between restoring force, stiffness, and displacement can be obtained. Then, the mechanical properties of BQZSS are verified with the finite element method. On this basis, the governing equations of the unit cell of the double-beam metamaterial are derived using Euler–Bernoulli beam theory. According to Bloch theorem and boundary conditions, the dispersion relation of the double-beam metamaterial is deduced, and behaviors of flexural wave propagation in beams are investigated. The effects of structure parameters on bandgaps and dispersion properties are studied, and the low frequency vibration bandgap mechanism is revealed. Finally, the frequency response function (FRF) of the double-beam metamaterial with a finite length is calculated in ANSYS to verify the bandgap characteristics given by a theoretical model. The results show that the double-beam metamaterial can yield multiple low frequency bandgaps at 100 Hz, 200 Hz, 300 Hz, and 500 Hz for suppression of flexural vibration components of transformers, which benefits from Bragg scattering (BS) and the blend of BS and LR mechanisms. The opening and closing of the low frequency bandgaps and the attenuation constants within bandgaps can be tuned by choosing parameters of beams. These findings suggest that the coupling between beams can lead to novel dispersion properties, which provides a new control approach for low frequency vibration and noise in power transformer. [ABSTRACT FROM AUTHOR]

• From the perspectives of electrical, thermal and vibrational properties, this paper summaries and analyses the valve reactor. • The calculation methods of core loss and core vibration under pulse excitation are summarized and extracted in this paper. • The equivalent resistance of the core and parameters of the magnetic materials, core dimensions and air gaps are analyzed. The valve Reactor (VR) is an indispensable protective element within High Voltage Direct Current (HVDC) system converters, susceptible to malfunctions such as overheating and localized deformation under the conditions of ultra-high frequency and discontinuous operational excitation. This work provides a comprehensive review of the latest research findings on the electrical, thermal, and vibrational properties of VR. Initially, this work utilizes circuit models to analyze the constituent components of various VR types and their electromagnetic properties under actual working conditions, with a profound exploration of the insulation technologies involving epoxy resin and insulated silicon steel coatings. Subsequently, this work incorporates finite element analysis (FEA) on the basis of loss calculation models and conventional thermal circuit models to explain the temperature properties of VR from a multi-physics perspective. Furthermore, this work integrates mechanical calculation models with FEA models to elaborate on the vibrational properties of VR under practical excitations and discusses optimization measures. Finally, this work envisions the future development directions of VR from the perspectives of electrical, thermal, and vibrational properties, and proposes optimization suggestions, providing valuable references for the improvement of VR design and condition evaluation. [ABSTRACT FROM AUTHOR]

Inclusions inevitably exist in steel plate, whose behaviour during rolling severely affects the quality of product. In this article, a finite element method was used to simulate the hot rolling behaviour of hard and soft inclusions in high silicon steel plates at different sizes, positions and shapes (circle and square) when the adhesion to the matrix were weak. The shape, relative position and dimensions around the inclusions after rolling were obtained. When the inclusions are hard, cracks are produced around the inclusions after rolling. When inclusions are soft, there are no cracks around the inclusions. Large hard inclusions are more likely to move to the plate surface. When the inclusions are in the position of 1/16 of the sheet, the relative distance between the inclusions and the surface of the sheets is significantly reduced, from 0.062 at the beginning to less than 0.02. Furthermore, the effect of the size and location of hard inclusions on the microscopic defects produced after rolling is discussed. The microscopic defects around the inclusions increase with increasing size and decreasing distance of the inclusions. [ABSTRACT FROM AUTHOR]

Electrification of off-highway vehicles is notoriously challenging due to extreme power density requirements. This article proposes and develops an axial flux machine integrated with a hydraulic pump to realize a single modular, electro-hydraulic machine to electrify off-highway vehicle implements. This integrated machine eliminates redundant bearings, couplings, and shaft seals, reuses surfaces, and enables direct cooling of the electric machine with the hydraulic fluid, to significantly increase power density. Three popular axial flux machine variants are first compared using a finite element analysis based design optimization approach. The single rotor, single stator variant is identified to be the most promising for integration with the hydraulic pump. Next, a multiphysics framework of the complete integrated hydraulic pump and axial flux machine is developed to characterize the design space. The results indicate promising potential for this concept to realize efficiency over 85% and power density over 5 kW/kg for the complete machine (electric machine, hydraulic pump, and thermal management system), while utilizing conventional materials (thin gauge silicon steel, N45 magnets, and enamelled copper wire). A prototype axial flux machine has been experimentally characterized and integrated with a hydraulic pump to demonstrate the integrated electro-hydraulic machine concept. [ABSTRACT FROM AUTHOR]

To reduce the iron loss, motor cores are designed with many layers of silicon steel sheets, and these sheets are elastically joined using the embossed regions. In this study, we investigate how the embossing position affects the joining strength using 0.5-mm-thick silicon steel sheets. Specifically, we embossed and stacked pairs of rectangular specimens and then conducted separation tests. The separation force increased as the embossing position moved further from the specimen's edge. In addition, finite element analysis predicted the radial compressive stress of the interlocked projections, and it exhibits similar variation to the experimentally measured separation force with the changing embossing position. [ABSTRACT FROM AUTHOR]

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Studies have substantiated that the vibration and noise produced by the iron core of an electromagnetic device are closely related to the magnetostriction of the iron core silicon steel sheet. Moreover, when the induction motor works under the condition of frequency conversion, the symmetry of the core silicon steel sheet will change, and the distribution of the vibration and noise field of the motor will be asymmetric, which will aggravate the vibration and noise. This paper completes the experimental measurement and analysis of the electromagnetic characteristics and magnetostrictive characteristics of silicon steel sheets. The magnetic field of a 1140 V/75 kW variable-frequency motor is calculated analytically based on the analytical method, and the stator/rotor magnetic induction intensity and permeance are calculated separately to obtain the air gap magnetic density and the radial electromagnetic force. The vibration and noise of the 1140 V/75 kW variable-frequency motor are analyzed by the finite element method, while the magnetization curve and magnetostrictive characteristic curve of a silicon steel sheet under different conditions are considered. An experimental platform is built to measure and analyze the vibration displacement and acceleration of the variable frequency motor, which verifies the correctness of the proposed scheme. Considering the influence of the magnetostrictive effect will make the result of calculating the vibration and noise of variable-frequency motors more accurate. [ABSTRACT FROM AUTHOR]

This article employs grain-oriented (GO) silicon steel in an axial-flux permanent magnet (AFPM) machine to improve its torque and efficiency. Rolling direction of the GO material have been studied to ensure the machine’s main magnetic flux passes through the easy magnetization direction. Based on the study of the electromagnetic characteristics of AFPM machine, GO silicon steel is laminated to form a stator according to a certain lamination direction. The torque and efficiency of the proposed machine with GO material shows an increase in comparison with that of the conventional non-oriented (NO) silicon steel machine under identical conditions. In addition, an equivalent magnetic circuit model is established to illustrate little difference of electromagnetic property under no-load condition for the yokeless stator AFPM using two kinds of silicon steel sheet. Furthermore, a AFPM machine with stator yoke is also established to highlight the superiority of GO in the application of the AFPM machine with yokeless stator. [ABSTRACT FROM AUTHOR]

Permanent magnet (PM) synchronous motors have become excellent alternatives for traditional induction and dc motors in numerous applications in recent years. Therefore, torque density and efficiency improvements in the development of PM synchronous motors have become a significant issue. In this study, various PM synchronous motor alternatives are proposed with both non-oriented (NO) and grain-oriented (GO) silicon steel material in the same stator in order to increase the power density and efficiency. A detailed performance comparison using 2-D/3-D finite element analysis (FEA) is completed and a feasible stator design is manufactured. The proposed design with GO material is also compared with a conventional PM motor with NO stator steel. As a result of the investigations, it is observed that the proposed motor with GO material in the stator has higher torque density and efficiency as opposed to the conventional PM motor. [ABSTRACT FROM AUTHOR]

This paper proposes a novel flux switching claw pole machine (FSCPM) with soft magnetic composite (SMC) cores. The proposed FSCPM holds advantages of the conventional flux switching permanent magnet machine (FSPMM) and claw pole machine (CPM) with SMC cores. As permanent magnets are installed between the stator claw pole teeth, FSCPM has good flux concentrating ability, and the air gap flux density can be significantly improved. The torque coefficient of FSCPM is relatively high due to the applied claw pole teeth and global winding. FSCPM is mechanically robust because there are no windings or PMs on its rotor. Moreover, the core loss of FSCPM is relatively low for the SMC material has lower core loss at high frequency compared with silicon steels. The topology and operational principle of FSCPM are explained first. Several main dimensions of the machine are optimized to achieve better performance, based on 3D finite element method (FEM). Furthermore, the rotor skewing technology is adopted to reduce the cogging torque and torque ripple. [ABSTRACT FROM AUTHOR]

This paper proposes a novel permanent magnet assisted synchronous reluctance (PMAREL) machine, the main structure of this machine is quite similar to that of traditional PMAREL machine, and the main difference is that the grain-oriented silicon steel is used to replace some part of the stator teeth. The rolling direction of the grain-oriented silicon steel is along the radial direction of the machine, thus the advantage of higher permeability and higher kneel point in this material can be used to release the flux saturation problem of the traditional non-grain-oriented steel used in the PMAREL machine when the applied current density is high. Firstly, the structure of both proposed novel and traditional PMAREL machines are optimized and the design parameters are determined. Secondly the electromagnetic and mechanical performance are compared in these two machines which includes the demagnetization analysis, mechanical stress analysis when the rotor at the maximum speed, torque ability, efficiency by using the finite element method (FEM). It can be seen that the problem of stator teeth saturation in the novel PMAREL has been alleviated, and compared with the traditional PMAREL machine, the novel PMAREL has higher efficiency, wider speed range and 7% higher torque ability. [ABSTRACT FROM AUTHOR]

To realize larger‐capacity "Hybrid‐core transformer: HBT", this research has assembled a 30‐MVA three‐phase trial HBT and evaluated the loss performances. The hybrid‐core consisting of the wound amorphous‐ and the stacked silicon steel‐cores, is expected having advantages of lower iron loss of the iron‐based amorphous material and the higher mechanical strength and saturation magnetic flux density of the silicon steels simultaneously. Three‐dimensional finite‐element method analysis revealed that the silicon steel core prevented over‐saturation of the amorphous core. The hybrid configuration enabled the design to have an approximately 10% higher magnetic flux density than configurations with only an amorphous core. We then assembled a prototype 30‐MVA three‐phase HBT designed on the basis of our investigation results. Operation tests demonstrated that the HBT has 62%‐reduced iron loss and 0.10%‐higher 50%‐loaded power efficiency from the conventional silicon steel core transformer. [ABSTRACT FROM AUTHOR]

This article presents the rotor optimization in an interior permanent magnet synchronous machine (IPMSM) with high-strength non-grain-oriented (NGO) silicon steel material. Different from simple replacement with high-strength NGO, this article presents a customized design to make the best use of rotor iron core material. Specific optimization of the rotor topology is presented, followed with simulation verification by finite element method (FEM). Based on the simulation results, the benefits and limitations of the optimization design with the replacement of high-strength NGO are listed. In order to further overcome the limitations of the presented optimization design, magnetic characteristics of the high-strength NGO laminations subjected to various tensile stresses are measured in the experiment. Finally, experimental results are analyzed, and the conclusions to employ high-strength NGO for IPMSM are summarized. [ABSTRACT FROM AUTHOR]

For the high-speed permanent magnet synchronous motors (HSPMSMs), their magnetic fields are more complicated with the rotating magnetization and harmonics considered. Furthermore, there are interaction effects on motor iron loss from high frequency, temperature, and compressive stress. In order to obtain the accurate HSPMSM iron loss calculation model, different iron loss models are proposed, in this article, considering these physical factors, and the iron loss model considering the interaction effect of the multiphysics factors is given. The magnetic field, temperature field, and stress field are analyzed for HSPMSM by finite-element method (FEM). Then, the proposed models are employed to calculate the iron loss of the silicon steel sheet and the prototype. The accuracy of the proposed iron loss model, which can consider the interaction effect of the multiphysics factors, is verified by the experimental test measurements on the prototype. [ABSTRACT FROM AUTHOR]

To improve output torque ability and reduce torque ripple in traditional synchronous reluctance motor (TSynRM), a new synchronous reluctance motor (NSynRM) is proposed in this paper. The rotor of NSynRM is composed of both grain-oriented silicon steel and non-oriented silicon steel. With the reasonable design of rotor structure, the torque of NSynRM has been improved and its torque ripple has been reduced greatly. Firstly, TSynRM and NSynRM are qualitatively compared by using the magnetic network method. Secondly, the main parameters of these two machines are optimized by using finite element method (FEM). Then the performance comparison between two optimized machines are carried out. Finally, the equivalent stress of these two machines at the maximum speed are analyzed. It can be seen that NSynRM can have 6.8% higher torque under rated load, 8% higher torque under maximum load, 17.5% wider constant torque operation region, and lower torque ripple compared with the TSynRM. [ABSTRACT FROM AUTHOR]

A 3-D coupled magneto-fluid-thermal model is established for temperature rise prediction in a ventilated dry-type transformer rated at 2500 kVA. In order to accurately estimate electromagnetic losses, a three-dimensional (3-D) transient finite element method considering the effect of eddy-current losses on the foil type windings is proposed. Besides, two orthogonal B-P loss curves are adopted to model the anisotropy of grain-oriented (GO) silicon steel. The non-uniform power losses of winding and core are mapped into the thermal field as heat sources. Moreover, the transformer structures such as the narrow struts, insulation barrier and clamps are considered to improve the computational accuracy of air velocity and temperature distribution. At last, the test of temperature rise has been carried out to verify the proposed model. [ABSTRACT FROM AUTHOR]

Controlling the profile and edge drop in the cold rolling process is crucial especially in applications involving silicon steel. In non-oriented silicon steel production, the work rolls shifting control is widely applied in 6-high tandem cold mills and the differences of the control characters of different stands have been gradually recognized. However, because of the lack of research on shifting control effect of separate stands and their influence between each other, controlling the edge drop by cooperatively shifting the work rolls of multiple stands is still impossible, so the mills' capability is not utilized efficiently. In this study, we develop a finite element method (FEM) model to investigate this issue. Based on the results of the FEM model, we conclude that work roll shifting of different stands leads to the independent control of edge drop, obtain the shifting control effect of different stands to their exit, and the attenuation effects by the following stands. Besides, we deduce that the approach to calculating the edge drop control characteristics should be modified to summation equation of the attenuation effects. The results of an experiment involving 6-high tandem cold mills are in agreement with the results of calculation with the FEM model and we demonstrate the high precision of the FEM model and the reliability of the subsequent analysis. Based on the edge drop control characters established, the control model and the cooperation strategy were designed and applied to the practical production, and significant improvements of edge drop and transverse thickness deviation were obtained. [ABSTRACT FROM AUTHOR]

• Abnormal heating of cable grounding line near three-phase reactor by finite element analysis. • Investigation into the impact of cable burial depth and cable laying on temperature elevation. • Effective shielding and safety assurance for the slot box. Cable termination near to three-phase dry-type air- core reactor (DAR) is prone to abnormal heating. In response to this problem, this paper firstly establishes the finite element model of the reactor and the cable and calculates the electromagnetic field distribution to obtain the current of the grounding wire of the cable armor layer. It is analyzed that the main reason for the abnormal temperature of the cable terminal is the eddy current in the grounding wire of the cable armor layer, which is caused by the leakage magnetic field of the reactor. Meanwhile, the influence of cable laying mode near the reactor on the current of armored grounding wire is further discussed. Secondly, the finite element model of the cable terminal is established and the temperature of the cable terminal is obtained by calculating the current-fluid-thermal coupling field. Considering the influence of adding shielding to reactor operation, the scheme of adding laminated silicon steel sheet slot box to cable is put forward and simulated. After adding slot box, the grounding wire current of armor layer is reduced by about 87% ∼ 89%. The test results show that when the input voltage of the coil is constant, the eddy current measured after installing the slot box decreases significantly, and with the increase of the coil voltage, the suppression effect of installing the slot box on the induced circulating current is better. This paper provides a certain reference value for the laying of cables near three-phase DAR in substations and the solutions to the abnormal heating of cable terminals. [ABSTRACT FROM AUTHOR]

Abstract Surface defects on metal strips can be generated during hot rolling from surface cavities and indents. The size and aspect ratio of the initial surface cavities present before rolling are critical parameters that determine the final configuration of the defect. The propagation of these defect through the full rolling process is detrimental to the surface quality of the end product, in particular for electrical steel where these type of defects may directly affect the magnetic properties of the final product. A finite element model was developed in the present research to simulate the evolution of surface defects in a high-silicon electrical steel subjected to a single pass hot-rolling operation. The surface defects were modelled as predefined cavities with various aspect ratios and a multi-scale approach was used to capture the large local deformation gradients at the vicinity of the initial cavities. A user-defined subroutine was developed to describe the material constitutive behaviour at different strain rates and temperatures based on the Sellars-Tegart model in ABAQUS/standard finite element package. The modelling results were validated by laboratory scale hot rolling experiments with respect to the measured rolling forces and the plastic deformation of the initial cavities. This study shows that buckling of the lateral sides and bulging of the floor of the initial cavities are the main mechanisms involved in the formation of sub-surface defects. The developed model can be used to predict the evolution of surface cavities and to optimise the rolling parameters in order to minimise the detrimental effect of these defects in the final stages of the hot rolling process. [ABSTRACT FROM AUTHOR]

Two types of surface-mounted permanent magnet synchronous machines (PMSMs) with the same physical dimensions but different stator core materials are comparatively analyzed, prototyped, and tested in this paper. In order to quantify the magnetization and loss characteristics of the stacked amorphous metal (AM) stator core, an experiment is conducted under different supply frequencies. Based on the data, the no-load iron losses, harmonic losses generated by the inverter-induced non-sinusoidal current harmonics, and the $d$ -axis and $q$ -axis inductances of two types of motors are comparatively analyzed by the finite-element method under different conditions and verified by experiments carried out on the two types of PMSM prototypes. The results illustrate that the AM PMSM has a characteristic of extremely low no-load iron losses, relative to the conventional silicon steel PMSM. [ABSTRACT FROM AUTHOR]

Local high iron loss may occur due to the deviation of magnetic flux from the rolling direction of electrical steel in the T-joint area of the transformer core. In this paper, to reduce the iron core loss in the T-joint region, a hybrid iron core model using nonoriented and grain-oriented magnetic materials is proposed. Three-dimensional magnetic field analysis considering the nonlinearity and laminated structure of the original and proposed iron core models is carried out by using the finite element analysis. The flux and iron loss distributions of the original and the hybrid cores are compared. The results show that approximately 2% iron loss reduction can be achieved by using the proposed hybrid structure. [ABSTRACT FROM AUTHOR]

No-load losses are caused by the magnetizing current that needed to energize the transformers core. These losses are constant and occur 24 h a day, regardless of the load. So, the customers should pay the fixed monthly cost for these losses. In recent years, amorphous alloy has been used to improve distribution transformers performance with the decrease in No-load losses and the increase in the efficiency of transformers. This paper outlines the 2605SA1 amorphous core as a new development of the amorphous alloy with a higher saturation induction. This paper presents a comparison between traditional distribution transformers and amorphous distribution transformers. Distribution of flux density in two different transformers with amorphous core and M5-type silicon steel core has been simulated using 3-D finite element modelling. The simulation and modelling results have been compared with the tests results of 630 kVA, 34.5/0.4 kV prototypes manufactured in the TEK TRANSFORMER factory in Turkey. A good agreement has been obtained between the simulation and experimental results. The simulation and test results show that amorphous core considerably (about 63%) reduces the no-load power losses as well as efficiency of transformers. [ABSTRACT FROM AUTHOR]

The structural and electrical parameters of leakage inductance transformers can significantly affect the efficiency, noise, and vibration of microwave ovens. The paper proposed a new iron core structure with finite element modeling and simulations of a leakage inductance transformer by both the electromagnetic field and system design simulation software. Different silicon steel sheet models were used for the upper and lower parts of the proposed iron core to reduce the loss and heat of the leakage inductance transformer. The iron core scheme was changed from the traditional E-I type to the E-E type. The feasibility of the new iron core scheme was tested by numerical results which showed that the maximum temperature rise of the leakage inductance transformer decreased significantly. [ABSTRACT FROM AUTHOR]

This paper presents the results of experimental trials carried out on a permanent magnet synchronous motor (PMSM) that uses a stator core made of a nanocrystalline magnetic material (FINEMET). It is demonstrated that the manufactured stator can reduce the PMSM total iron loss by 64% to 75% compared with an equivalent motor using a stator made of conventional non-oriented silicon steel. The experimental results are confirmed by 2-D finite-element analysis. [ABSTRACT FROM AUTHOR]

The integration effects on flatness control during hot rolling process is studied for meeting the requirement of schedule-free rolling (SFR) campaigns of non-oriented electrical steel strips with identical width. A 3D finite element model for elastic deformation of rolls is built by ANSYS. The integration effects of lubrication, asymmetry self-compensating work rolls (ASR), and varying contact back-up roll (VCR) contours on flatness control are comparatively analyzed. An improved strip profile, flatness, and rolling stability are achieved by combining these technologies. The total rolling coil number is increased from 70 to 100 within a rolling campaign. The lateral stiffness of roll gap is increased by 10.3 and 12.75% in the early and later rolling stage, respectively. [ABSTRACT FROM AUTHOR]

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]

Experimental and numerical investigations have been carried out to study the effect of processing parameters on edge cracks in cold rolling process of silicon steels. The onset of edge cracks has been simulated by using finite element method (FEM) based on the Gurson–Tvergaard–Needleman damage model. Factorial design and Taguchi experimental design methods have been proposed to analyze the effects of reduction ratio, tension, work roll diameter, and friction coefficient on the formation of edge cracks. Parametric studies indicated that with the increasing of reduction ratio, friction coefficient, and tension, the crack length increases. A bigger work roll is beneficial to restrict the edge crack growth as well. The rank according to the impact degrees on the crack initiation from high to low is reduction ratio, tension, work roll diameter, and friction coefficient. Meanwhile, the combined effect curve of reduction ratio and tension on crack length was obtained which was validated by the experimental results as well. [ABSTRACT FROM PUBLISHER]

In this paper, a switched reluctance motor (SRM) with amorphous cores was designed and assembled. Comparing with another SRM that was made of silicon steel (50DW360) cores, the experimental results show that the core loss of amorphous core is only 10% of the silicon steel core at 600 Hz and 0·5 T and the maximum value of phase inductance in amorphous prototype is lower than that of 50DW360 by 7%. The motor performance, including flux distribution, copper loss, iron loss and efficiency, was simulated and predicted by the finite element analysis (FEA) method using Infolytica software. The results show that the iron loss of SRM with amorphous cores can be reduced by 90% and efficiency can be improved by approximately 2%. [ABSTRACT FROM AUTHOR]

Magnetostriction in grain-oriented (GO) electrical silicon steel arises vibration and noise of the transformer core, especially when operating under direct current (dc) bias. In this paper, the anisotropy of magnetostriction of GO silicon steel sheets along the rolling direction (RD) and other directions deviated from RD was measured based on a standard single-sheet measurement system. The effect of applied stress on magnetostriction was also measured and analyzed. The magnetostriction under alternating magnetic field plus dc biased field was measured and a constitutive equation considering single-valued curves of magnetostriction under dc bias when incorporated with magnetic finite-element analysis was investigated. Considering a simple model as an example, the effectiveness of the proposed modeling method was verified by the comparison of simulation data and measured ones. [ABSTRACT FROM AUTHOR]

A novel 3-D magnetic properties tester for laminated silicon steel specimen has been designed and constructed. The magnetization structure is the critical part of the tester especially for the magnetic properties of the laminated silicon steel in perpendicular direction of grain oriented. To guarantee the experimental precision and accurately analyze the 3-D magnetic properties of the laminated silicon steel, a symmetrical 3-D magnetic flux path in the magnetization structure fit for given dimension of specimen has been calculated and modeled. Magnetic flux in each direction has been homogenized and concentrated on the top of the core poles through finite element analysis. Therefore, magnetic properties in each direction of the laminated specimen can be really concerned and analyzed in practical engineering. [ABSTRACT FROM AUTHOR]

This paper studies the homogenization of quasi-static and nonlinear Maxwell's equations in grain-oriented (GO) silicon steel laminations. GO silicon steel laminations have multiple scales, and the ratio of the largest scale to the smallest scale can be up to 106. Direct solution of three-dimensional nonlinear Maxwell's equations is very challenging and unrealistic for large electromagnetic devices. Based on the magnetic vector potential and the magnetic field, respectively, we propose two macroscale models for the quasi-static Maxwell's equations. We prove that microscale solutions converge to the solutions of the macroscale models weakly in H(curl, Ω) and strongly in L2(Ω) as the thickness of lamination tends to zero. The well-posedness of the homogenized model is established by using weighted norms. Numerical experiments are carried out for a benchmark problem from the International Compumag Society, TEAM Workshop Problem 21c-M1 [Z. Cheng, N. Takahashi, and B. Forghani, TEAM Problem 21 Family, International Compumag Society, 2009. http://www.compumag.org/jsite/team.html]. The numerical results show good agreements with the experimental data and validate the homogenized model. [ABSTRACT FROM AUTHOR]

We investigated the torque characteristics and the motor efficiency of interior permanent magnet synchronous motors (IPMSM), in which a rotor core consists of high-strength nonoriented electrical steel, as-cold-rolled nonoriented electrical steel, and conventional nonoriented electrical steel with various bridge widths. Furthermore, we analyzed deformation behavior of the rotor core during operation by finite element method. The motor of the high-strength nonoriented electrical steel generated greater magnet torque than that of the conventional nonoriented electrical steel. Although the high-strength nonoriented electrical steel had much higher iron loss than the conventional nonoriented electrical steel, the motor efficiency decreased only slightly. A reduction in the bridge width of the rotor core significantly enhanced the torque characteristics and the motor efficiency of IPMSM. The high-strength nonoriented electrical steel effectively suppressed the deformation of the rotor core with its excellent mechanical properties, and the suppression enabled us to reduce the bridge width sufficiently. Accordingly, a magnetically optimum rotor core design will be realized with the high-strength nonoriented electrical steel, and the performance of IPMSM will be significantly enhanced, particularly in traction motors for electric vehicles and hybrid electric vehicles and compressor motors for energy-efficient air conditioners. [ABSTRACT FROM PUBLISHER]

A transverse-flux tubular linear machine with novel gear-shaped teeth for high force density is proposed. The teeth can be formed by silicon steel laminations or permanent magnets for a tubular linear switched reluctance or tubular linear hybrid motor. With the unique improved teeth structure and short magnetic circulation paths, larger propulsion force output can be obtained with reduced mover weight and volume. Simulation based on finite element method (FEM) verifies the validity of the proposed machine design. The proposed machines are compared with other transverse-flux linear machines. Results show that the proposed tubular motors exhibit better output performance with a higher force-to-volume ratio. [ABSTRACT FROM AUTHOR]

Abstract: Through-thickness shear strain distribution in cold rolled non-oriented silicon steel under different roll gap geometries and friction coefficients was analyzed by finite element method (FEM). Cold rolling textures were also investigated quantitatively to validate the calculated shear strain distribution. The results showed that both direction and magnitude of shear strain through thickness depend sensitively on the two rolling parameters. The coupling effect of roll gap geometry and friction was satisfactorily explained based on their contributions to shear strain and the involved mechanisms. A shear strain distribution diagram (SSDD), which can clearly characterize the shear strain state with roll gap geometry, friction and through-thickness position as variables, was proposed to serve as a convenient tool for through-thickness shear strain control. [Copyright &y& Elsevier]

This paper presents results of magnetic characteristic analysis of a three-phase generator utilizing grain-oriented silicon steel sheets. In the analysis, the finite element method taking account of the two-dimensional magnetic properties is used to make clear rotational iron loss distributions. In this paper, the knowledge obtained in the numerical simulations by means of the integration-type dynamic E&S modeling is reported. Also, the measurement results of a prototype generator designed with the magnetic characteristic analysis are shown. [ABSTRACT FROM AUTHOR]

A systematic approach for analysing vibration-related problems of electrical machines, integrating both complex electromagnetic and rotordynamic analyses, is completely presented with an in-house finite-element solution module, formulated from related theories in rotordynamics. The electromagnetic analysis processes with the MagNet software are described herein to obtain the performance curves of electrical machines. They are integrated into the equation of motion to investigate the corresponding vibration characteristics. Based on the previously published work, the squirrel-cage-type induction motor is employed as an extended case study to demonstrate the integrated procedure. Three types of silicon steel core materials are considered in order to explore their effects in the dynamic properties of the system. Also, what happens on the vibration amplitude of rotor critical positions at the instant right before and after passing the critical speed are investigated thoroughly. The corresponding results exhibit that the complete procedures in using the proposed methodology can solve the reliability issues of electrical machines effectively. [ABSTRACT FROM AUTHOR]

Abstract: Using traditional laser cutting technology, it is easy to produce molten slag in laser cutting silicon steel sheet. The main reason is the inevitable oxidizing reaction in the process caused by the use of oxygen as the aided gas. As a common solution, high pressure and high purity N2 or an inert gas is therefore used instead of oxygen. Although the cut quality is improved, the cutting efficiency is reduced because of the lack of energy generated from an exothermic oxidation reaction. The technology used in this paper is to employ a newly developed cyclone slag separator. The slag separator is located under the workpiece to form rotating gas flow for controlling the direction of the flowing slag gas. Adopting the new technology reported here, oxygen is still used as the aided gas. The experiments prove that, by controlling the technical parameters reasonably tightly, glossy and dross-free cutting kerfs are obtained for reduced laser power. The gas flow acting under the workpiece is simulated using the finite element method (FEM). The operating law of the rotating gas flow is verified by ANSYS, which provides an academic basis for controlling the flowing direction of the slag gas. [Copyright &y& Elsevier]

Three-dimensional finite element simulation has been carried out to understand better the crack initiation and growth at the edge side of silicon steel sheet during cold rolling, which is attributable to elastic deformation of work roll, i.e., roll bending. Strain-controlled failure model was coupled with finite element method and a series of FE simulation has been carried out while three different roll bending modes are considered. FE simulation shows that the negative roll bending mode during rolling affects significantly the crack initiation behavior. When the strain for failure was reduced by 20%, number of elements removed was increased by about 305%. If an initial crack with 2.5mm in length was assumed on the strip, the initial edge crack propagated toward inner region of strip and the propagated length is about 10times of the initial edge crack length. [ABSTRACT FROM AUTHOR]

This paper presents an improved magnetic reluctivity model for vector magnetic properties of anisotropic electrical steel sheet based on Chua-type model using Fourier series expansion of measured B and H waveforms in the viewpoint of engineering application. In the modeling, B-spline surface interpolation is adopted to obtain smooth approximation of measured data. The accuracy of the proposed magnetic reluctivity model is verified by comparing its modeling results with experimentally measured Band H-waveforms with 3OPG11O grain-oriented silicon steel sheet. The nonlinear finite element (FE) formulation is also derived to incorporate the proposed reluctivity model, and applied to magnetic field analysis of a single phase transformer core model. By comparing the numerical results with experimental ones, the effectiveness of the reluctivity model and FE formulation is investigated. [ABSTRACT FROM AUTHOR]

Despite the apparent relative simplicity of the wound toroidal geometry, numerical modeling techniques are very difficult to implement due to the inherent large mesh size required to model a laminated core or spiral geometry. Recent advancements in computing capabilities have made the simulation and the study of such devices more feasible. Finite-element modeling of toroidal cores wound from grain-oriented electrical steel was conducted to accurately represent their magnetic circuits in order to calculate the internal magnetic flux distribution, its interaction with core geometry, and to be able to predict the associated magnetic losses. The general flux distribution trends agree with measured results from identical cores. The interlaminar flux and the associated induced planar eddy currents were also calculated. The measurements were performed using a series of search coils enclosing every five turns. In each case, the core was magnetized at 50 and 400 Hz under controlled sinusoidal flux density up to 1.5 T. [ABSTRACT FROM AUTHOR]