Magnetic Steel Research Articles

Impact of Magnetic Core Steel Grade on the Performance of Synchronous Reluctance Motor with Transversally Laminated Anisotropic (TLA) Rotor Core for e-Auto rickshaw Application

This paper investigates the complete performance impact analysis of Synchronous Reluctance Motor (SynRM) designed for an electric Auto Rickshaw application. Here, different magnetic core steel grades are used for the same motor geometry with the TLA rotor. As it is an electric traction application, proper operation of the motor under various operating specifications is critical. Therefore, a thorough study is conducted using the finite-element method combined with an experiment-based magnetic material model at rated speed. Based on the magnetization and hysteresis characteristics of the steel sheets, variations on the performance indexes such as the average torques, torque ripples, and iron losses by using a different stator and rotor materials are investigated. Some valuable comparison results are provided through simulation and experimental validation results are shown with a prototype built.

Electromagnetic Vibration System Designed for De-Stressing Welded Joints from Large Metal Constructions

The paper presents an electromagnetic installation for producing vibrations, used in the de-tensioning of welded joints of welded constructions. They are also presented novelty elements regarding the domains of use of these types of installations, as well as the benefit of their use. They are highlighted the component parts of these types of installations. This type of electromagnetic installations can be used at the treatment of welded joints used only on magnetic steels. The results obtained with this type of installations are obvious. This vibration system can be used to de-stress welded joints and can successfully replace other types of conventional heat treatment. The components of this installation were purchased commercially. That makes possible that this type of installation can be easily built. The installation has designed a protection system for high voltages and currents. The main purpose of using this type of installation is to reduce the costs of conventional heat treatment, used at welded metal constructions. The installation can be used without strict protection rules. If we talk about the results, we can say that this type of treatment can bring significant economic benefits.

Magnetostatic determination of variations of internal stress in magnetic steels

This paper explores the possibility to measure changes in internal stress in ferromagnetic steels using magnetostatic methods. The device consists of a permanent magnet placed close to the steel piece and a magnetic probe between both elements. The magnetostatic field measured by using the probe is partially due to the magnetization of the steel piece. Internal stress variations in the steel alter its magnetic permeability due to the magnetoelastic effect, varying the magnetostatic field measured by using the probe. For the device we present here, the relative variation of the measured magnetic field is of the order of 1.7 × 10−5/MPa of internal stress.

Mathematical model of the technological vibratory unit with electromagnetic excitation

The mathematical model of the technological vibratory unit with electromagnetic excitation is considered to its features that are important for the dynamic design problems. The model is based on the differential equations of electrical balance and mechanical balance, taking into account the mobility degree of inertial masses with spring linkages. The vibratory unit vibration properties are analyzed concerning the power voltage and frequency coupling, interacting inertia masses mobility degree, spring linkages properties, magnetic core steel magnetizing characteristic non-linearity, leakage fluxes, electric, magnetic and mechanical energy losses. The research performed for dynamical design problem solution is distinguished by a novel approach to the estimation of the capability of changing vibration properties of the movable operating element of the technological vibratory unit with an additional mass attached to it. The model design technology based on the structural modelling method supported by Matlab Simulink is proposed. The research results can be useful for specialists in vibration engineering, machines and devices durability dynamics and vibroprotection.

Метод сбора нефти в ледовых условиях с использованием магнитного поля и тонкодисперсного магнетита

The oil spill response using skimmer systems in the glacial seas continues to be relevant in world practice. A complex approach based on the combination of oil slick dispersion by solid fine magnetic particles and skimmer cleaning, the operative parts of which are equipped with metallic magnetized bristles, has been proposed as a promising and innovative solution. Application of finely dispersed magnetite – ferromagnetic spherical particles (iron oxides) as fine solid particles to create stable Pickering emulsions with formation of oil-ferromagnetic units is considered. Mathematical modeling has been performed to estimate the possibility of extraction of such oil-ferromagnetic units from water-oil emulsion under the influence of nonhomogeneous magnetic field created by magnetized steel bristles of skimmer operative parts. The results obtained confirmed the possibility of a practical application of the solution proposed by the authors to improve the efficiency of mechanical cleaning of oil spills in glacial seas.

Optimization and Modelling of Turbidity Removal of Sewage using High-Gradient Magnetic Separation (HGMS) by Response Surface Methodology (RSM)

Endless industrial development and growing society occasionally create an enormous volume of wastewater, which leads to some issues on wastewater treatment. Existing conventional screening processes have various limitations and drawbacks. Therefore, this study investigated the use of a combination of non-corrosive stainless steel wool and a permanent magnet to increase magnetic gradient, hence reducing suspended matter in sewage through turbidity test. An approach for optimizing the reduction of suspended matter through turbidity analysis was conducted using central composite design (CCD) under response surface methodology (RSM). Three critical independent variables, such as magnet strength, circulation time, and steel wool, and turbidity removal as the response, were further studied to analyze their interaction effects. As a result, an optimal value of turbidity removal was found at 90.3% under the specified optimum conditions of magnet strength of 245 mT, 116 g of non-corrosive stainless steel wool, and 16 h of circulation time. Statistical analysis had shown that the magnet strength, circulation time, and steel wool significantly affected the turbidity removal performance. Furthermore, design of experiment was significantly verified by a small range of error between predicted and actual data. Consequently, a higher gradient of magnetic separation was proven to effectively remove suspended matter using inexpensive non-corrosive stainless steel wool without using magnetic adsorbent. Thus, the suggested approach was found to be cost-effective and environmentally friendly for sewage treatment.

Positive effects of aligned steel fiber on bond behavior between steel rebar and concrete

A new steel fiber reinforced concrete (SFRC) structure is proposed to improve the bond performance between steel rebars and concrete by aligning the limited steel fibers closely around the magnetized rebar, which is achievable to have both adequate steel fibers around rebar for high steel-concrete bonding and appropriate fiber content for good fluidity of concrete. An experimental test is performed to verify the effectiveness of the new structure. 41 specimens are designed and subjected to pull-out test to observe the effects of rebar magnetization, concrete consolidating condition and steel fiber content on bond behavior between steel rebars and SFRC. Results verify the positive effects of the new structure on bond behavior under the suitable conditions. Steel fibers can be aligned closely around the magnetized steel rebar and consequently increase bond behavior. In the present test, the average increments of bond strength are 28.2% and 20.8% for pull-out and splitting specimens as the magnetization intensity increased form 0 mT–30 mT, respectively. The maximum increment is up to 50.0%. Steel fiber shows dual roles to bond strength since it increases the concrete strength with deteriorated fluidity. The recommended content of steel fiber is about 0.25%–0.75% for the proposed structure. And, self-consolidating concrete with good fluidity is required for the movement of steel fiber under the attracted force from the magnetized rebar.

Theoretical research on magnetization and demagnetization process of electrohydraulic servo valve with permanent magnet torque motor

The magnetization and demagnetization process of electrohydraulic servo valve with permanent magnet torque motor is the last manufacturing process of electrohydraulic servo valve before its service, which has a significant effect on the output characteristics and magnetic stability of both torque motor and electrohydraulic servo valve. However, the previous studies mainly focus on the static state of the magnetic circuit instead of the changes of the magnetic steel’s states while operating magnetization and demagnetization process of torque motor, which causes many issues such as the unpredictability and inaccuracy of magnetization and demagnetization process. In this paper, a set of theoretical models are proposed to describe this entire magnetization and demagnetization process more accurately aiming at this issue. Firstly, a detailed magnetic circuit mathematical model of permanent magnet torque motor before demagnetization is established according to two kinds of magnetic circuits. Secondly, different from the existing research, in this paper, taking the variety of internal reluctance and magnetomotive force of magnetic steel into consideration, an equivalent method is presented by dividing the B-H curve of the magnetization and demagnetization process into several segments. Finally, the finite element method is used to verify the accuracy of the proposed mathematical model. The research results show the proposed model can accurately calculate the magnetic flux density of magnetic steel at any time and even the air gap’s magnetic flux and the output torque after the magnetization and demagnetization process. This research can help to design the magnetization and demagnetization process such as demagnetizing current to make sure the toque motor meets the requirements, which has an important guiding significance to design and conduct the magnetization and demagnetization process of electrohydraulic servo valve with permanent magnet torque motor.

Nuclear magnetic resonance and surface-assisted laser desorption/ionization mass spectrometry-based serum metabolomics of kidney cancer

Kidney cancer is one of the most frequently diagnosed and the most lethal urinary cancer. Despite all the efforts made, no serum-specific biomarker is currently used in the clinical management of patients with this tumor. In this study, comprehensive high-resolution proton nuclear magnetic resonance spectroscopy (1H NMR) and silver-109 nanoparticle-enhanced steel target laser desorption/ionization mass spectrometry (109AgNPET LDI MS) approaches were conducted, in conjunction with multivariate data analysis, to discriminate the global serum metabolic profiles of kidney cancer (n = 50) and healthy volunteers (n = 49). Eight potential biomarkers have been identified using 1H NMR metabolomics and nine mass spectral features which differed significantly (p < 0.05) between kidney cancer patients and healthy volunteers, as observed by LDI MS. A partial least squares discriminant analysis (OPLS-DA) model generated from metabolic profiles obtained by both analytical approaches could robustly discriminate normal from cancerous samples (Q2 > 0.7), area under the receiver operative characteristic curve (ROC) AUC > 0.96. Compared with healthy human serum, kidney cancer serum had higher levels of glucose and lower levels of choline, glycerol, glycine, lactate, leucine, myo-inositol, and 1-methylhistidine. Analysis of differences between these metabolite levels in patients with different types and grades of kidney cancer was undertaken. Our results, derived from the combination of LDI MS and 1H NMR methods, suggest that serum biomarkers identified herein appeared to have great potential for use in clinical prognosis and/or diagnosis of kidney cancer.Graphical abstract

Разработка многоканальной системы управления многофазным синхронным электроприводом с улучшенными виброшумовыми характеристиками

Constantly increasing requirements for the performance of electromechanical systems include the task of improving the vibration and noise characteristics of the electric drive. Currently, this problem is solved mainly by using traditional three-phase systems. The transition to a multiphase version of the electric drive construction opens up new opportunities for its solution. The aim of the study is to improve the vibration and noise characteristics of the electric drive through the development of a multiphase control system that provides targeted formation of the field configuration in the gap of a multiphase electric machine. To conduct the research, the model of a multiphase synchronous motor proposed by the authors was used. The model considers the spatial non-sinusoidality of the field distribution in the gap and enables to represent the engine as a set of parallel substructures, the number of which depends on the number of phases. The technique to design a synchronous motor with an arbitrary number of winding phases based on the field model of the machine has been proposed. The correctness of the results obtained is ensured by the real geometry of the magnetic circuit and steel saturation. The multi-channel control system of the electric drive, characterized by the targeted formation of field configuration in the gap of a multiphase electric machine has been proposed. The calculation model of the electric drive has been developed. The model combines the field model of the engine and the control system. The engine model is implemented in the ElСut software package, the control system model is implemented in the MatLab (Simulink) complex. Compared to the traditional three-phase design of the electric drive with a sinusoidal supply voltage, the options for forming a field in the gap of a synchronous motor considered in the article provide a reduction in ponderomotive force by 8–14 %. The engineering methodology for designing an m-phase synchronous permanent magnet motor with permanent magnets and the structure of the multi-channel control system can be applied when developing electric drives with improved vibration and noise characteristics.

Non-grain oriented electrical steel photomicrograph classification using transfer learning

Among the many factors that contribute to achieving a sustainable and efficient economy is the raw material of machinery and equipment of strategic sectors. Non-grain oriented (NGO) electrical steel is used in the manufacturing of electric motors. Therefore, it is directly related to the electromagnetic efficiency of engines both in industry and in homes. This work aims to develop an intelligent 1.26% Si NGO electrical steel photomicrograph classification system to assist in the identification of better energy-efficient steel. The concept of Transfer Learning was used to apply Convolutional Neural Network architectures as feature extractors. Traditional machine learning classifiers are applied for coherent categorization of material efficiency. From the results, it is noted that the combination of the InceptionV3 architecture with the k-nearest neighbors classifier reached 100% accuracy and F1-Score. The average extraction time and test time were approximately 15 and 0.920μs, respectively. Given these results, the literature on this application is surpassed. The best extractor-classifier combination is available in an Internet of Things (IoT) system. Therefore, a professional can freely make use of the proposed approach to assist them in identifying low magnetic loss electrical steel.

RADIO ENGINEERING SYSTEM IDENTIFICATION OF METALS ON THE BASIS OF EDDY-CURRENT CONVERTERS

Context. The task of creating a radio system (RS) for identifying metals in the middle of subgroups of magnetic and nonmagnetic metals based on eddy current devices (ECD) is considered. The object of study is the radio identification system.Objective. Development of a radio system that allows you to expand the possibilities of ECP by identifying a metal in a subset of non-magnetic (copper, gold, silver, etc.) and magnetic (steel, nickel) materials.Method. A block diagram of the RS, which uses the processing of ECD signals in the time and spectral regions, is proposed. PC allows to identify the type of metal from which the control object (CO) is made, within the subsets of non-magnetic and magnetic materials, which allows to increase the probability of detecting CO hidden in a dielectric medium, made of non-ferrous, precious or ferrous metals.The validity of the results obtained from the verification of the technique was tested on a laboratory model of the PC, which consists of an analog eddy current part and a microcontroller with ADC to transfer data to a laptop, which implements the methods of signal processing. The article proposes the hypothesis of an informative parameter and a mathematical model that explains the causes of the signal and its form. The possibility of using RS to solve the problem of metal identification within a subset of non-magnetic and magnetic materials has been experimentally confirmed.Conclusions. Experimental studies carried out confirmed the efficiency of the proposed RS and the methods for processing the ECP signal, the software that implements it, which allows us to recommend it for the development of devices for identifying the metal from which the test object is made. Prospects for further research are to adapt mathematical and software not only to the base of metal images, but also to create images of complex objects, which will make it possible to identify a hidden metal object and thereby expand its capabilities.

A New Method for Detecting Initial Position of IPMSM Rotor

Aiming at the speed sensorless control system of permanent magnet synchronous motor which embedded in rotor magnet steel, a new method for detecting the initial position of the rotor is proposed in this paper. This method is injecting a high-frequency rotating voltage to generate a high-frequency current in the stator windings that contains the spatial position information of the rotor. Compared with the traditional high-frequency injection method, this paper uses Discrete Fourier Transform (DFT) to demodulate high-frequency current. It avoids the signal phase delay caused by the use of a large number of filters when demodulating the traditional heterodyne method. At the same time, this method has nothing to do with the initial phase of the injected signal. Compared with the heterodyne method, the extracted rotor position angle is more accurate, and the structure is simple Number system. The validity and feasibility of the method are verified by simulation and experimental platform based on dSPACE.

Substitution Effect of Magnetic Materials in Halbach Cylinder for Magnetic Refrigerators

In this paper, we present the magnetic refrigeration by magnetocaloric effect, for which the magnetic flux distribution has been modified in the Halbach cylinder. The insertion of a soft magnetic rod in the bore led to the alternating magnetic field with two regions of high flux density for magnetization and two regions of low flux density for demagnetization of magnetocaloric materials in the annular gap. The two-dimensional numerical simulations by the finite element method using COMSOL Multiphysics and Poisson SUPERFISH demonstrated the substitution effect of neodymium–iron–boron permanent magnets by soft magnetic low-carbon steels. The optimized soft magnetic cross-sectional area of 0.04 m2 in the Halbach cylinder gave the maximum flux density of 2 T in the air gap, comparable to the peak field of existing prototypes. The flux density is further increased and became the largest when the ratio of external to internal radius of the cylinder is at the maximum. The cooling performance is also affected by the size of the cylinder, and the substantial value is obtained in a practical design with reserved air gap for magnetocaloric materials.

Microcontroller-based magnetometer using a single nitrogen-vacancy defect in a nanodiamond

The measurement of magnetic properties of various physical systems with nanometric spatial resolution raises interest in areas such as materials science, biotechnology, and information storage and processing. In the present work, a microcontroller-based magnetometer was built using a single nitrogen-vacancy defect in a nanodiamond. The implemented nanomagnetometry method is simple and relies on the frequency modulation of the nitrogen-vacancy defect electron spin resonance using square pulses of an externally applied magnetic field and employs a single microwave source. The developed system has a reasonable sensitivity of 4 μT/Hz and is able to measure magnetic field variations at a rate of around 4 mT/s. This system was used for nanoimaging the inhomogeneous spatial magnetic field profile of a magnetized steel microwire, and a spatial magnetic field gradient of 13 μT/63 nm was measured. Besides its usefulness in nanoscale imaging of magnetic fields, the present work can be of interest in the development of compact nanodiamond based magnetometers.

Improved Evaluation of Magnetic Loss Inside Silicon Steel Laminations Under 3-D Multi-Harmonic Magnetizations

An improved method is presented to study the efficient numerical modeling of stray-field loss in magnetic shielding excited by a 3-D harmonic magnetic field. The experimental platform is established to obtain the magnetic properties and loss model of the silicon steel lamination under harmonic magnetizations. Experimental determination is improved for more accurate stray-field loss based on the engineering-oriented model TEAM Problem 21c-M1. Prediction and evaluation of stray-field loss and additional iron loss due to harmonic excitations are achieved by special treatment of material properties in the numerical calculation of the harmonic magnetic field.

Iron-Loss and Magnetization Dynamics in Non-Oriented Electrical Steel: 1-D Excitations Up to High Frequencies

This paper presents a thorough introduction to and application of the Parametric Magneto-Dynamic (PMD) model of soft magnetic steel sheets. The theoretical background is reviewed, and two different ways are discussed to account for the viscosity-like effects originating from microscopic eddy currents. This is followed by the theoretical calculation of magnetization dynamics and dynamic hysteresis loops in Non-Oriented (NO) electrical steel. Both classical and viscosity-extended approaches are discussed, with respect to the ability of replicating the dynamic hysteresis loop shape and iron-loss under sinusoidal excitation waveforms up to high excitation frequencies. Comparisons against measurements are analyzed for M400-50A and M235-35A NO electrical steel over a wide range of magnetic flux density and excitation frequencies. The proven accuracy and efficiency of the PMD model make it a valuable tool for the calculation of iron losses in electrical machines and transformers, as well as for an in-depth study of magnetization dynamics in individual laminations.

Design and Vibration Optimization of Direct Current Motor of Permanent Magnet of Rectangular Magnetic Steel

Direct current motor of permanent magnet (PMDCM) is widely used at present. To optimize its operating performance and vibration characteristics, a new PMDCM of rectangular magnetic steel was developed. The co-simulation was conducted based on RMxprt and MAXWELL. The simulation results verify that the output power and torque meet the design requirements. Then the cogging torque of the designed motor was analyzed and optimized by using response surface method. The influence degree of each factor on cogging torque was analyzed. When factor A, the factor B, and factor C are 33.51mm, 2.42mm, and 1.50mm, the root-mean-square (RMS) value and the maximum value of the cogging torque are smallest. The fitting accuracy of the two regression equations of RMS and maximum cogging torque is 94.30% and 97.26%. To further verify the correctness of analysis results, the optimized motor and reference motor were manufactured and the vibration velocity data at different positions were measured. The measured data shows that the maximum and average data of vibration velocity at measuring point 1 are decreased by 18.99% and 19.03% and the maximum and average vibration velocity at measuring point 2 are decreased by 9.73% and 4.70%. The method of vibration reduction is effective. The proposed optimization scheme and method may be extended to other motor for reducing vibration.

Study and Optimisation of Process Parameter in Turning Of EN 45 - Spring Steel Material Under Dry And MQL Conditions

Minimum quality lubrication has shown a noticeable changes with machining outcomes. MQL is one of updated technologies that have been prevailing in contributions towards production and environment enhancement. Present papers deals with the turning of EN 45 steel material which is commonly known to be spring material. En 45 one of the magnetic steel material with low manganese and high amount of carbons is turned under dry and MQL condition. DOE has been prepared with L9 taguchi. Machining factors of speed (75, 100, 125 m/min), feed (0.1, 0.2, 0.3 mm/rev) and depth of cut (0.3, 0.6, 0.9 mm). The surface roughness were optimized by considering the machining parameters of speed, feed, and depth of cut. For both the condition dry and MQL it was observed that speed at 125m/min, feed at 0.1 and depth of cut at 0.3mm was found optimum condition. The regression equation and mathematical model was generated using the experimental data. Furthermore the ANOVA analysis was performed and observed that in case of dry turning speed found to be most influencing parameter and in case of MQL turning Feed was found to be most influencing parameter.

Comparison of Preisach and Congruency-Based Static Hysteresis Models Applied to Non-Oriented Steels

Two hysteresis models are investigated for modeling static hysteresis phenomenon in nonoriented magnetic steels. First, the static Preisach model is studied, and two types of experimental data, i.e., first-order reversal curves (FORCs) and concentric hysteresis loops, are employed to identify the weight function. Due to negative values in the obtained experimental weight functions, the resulting Preisach models show nonphysical behavior. To eliminate this nonphysical behavior, an optimization procedure is applied to remove these negative values. The nonphysical behavior is resolved in the modified Preisach model; however, the model still has poor accuracy for asymmetric loops. Alternatively, a new congruency-based static hysteresis model is proposed. In this model, third- or higher-order reversal curves are approximated using measured FORCs and second-order reversal curves (SORCs) by means of a congruency regularity. According to this regularity, any third- or higher-order reversal curve is congruent to SORCs with the same reversal point. A 3-D piecewise interpolation function is employed to interpolate the measured major loop, FORCs, and SORCs. The proposed model results are compared with quasi-static measurements. The comparison reveals that the model is capable of approximating the magnetization curves for the measurements containing complex-shaped $B$ waveforms with a relative energy error of less than 4%.