Browsing by Author "Singh, Deepak"
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Item Analytical Model for magnetic Anisotropy Dedicated to Non-Oriented Steel Sheets(Emerald, 2015) Martin, Floran; Singh, Deepak; Belahcen, Anouar; Rasilo, Paavo; Arkkio, Antero; Haavisto, Ari; Sähkötekniikan ja automaation laitos; Department of Electrical Engineering and Automation; Sähkötekniikan korkeakoulu; School of Electrical EngineeringRecent investigations on magnetic properties of Non-Oriented steel sheets enhance the comprehension of the magnetic anisotropy behavior of widely employed electrical sheets. Our investigation consists of developing an analytical model to consider these magnetic properties while modelling electromagnetic systems. From rotational measurements, the anhysteretic curves are interpolated in order to extract the magnetic energy density for different directions and amplitudes of the magnetic flux density. Furthermore, the analytical representation of this energy is suggested based on statistical distribution which aims to minimize the intrinsic energy of the material. Our model is finally validated by comparing measured and computed values of the magnetic field strength.Item Calorimetric Measurement of the Stator Core Losses Caused by Manufacturing(Aalto University, 2011) Singh, Deepak; Sähkötekniikan laitos; Arkkio, AnteroThis thesis is a part of the research on the effect of the manufacturing process on the core losses of the electrical machine. Within this thesis, a special test setup, that has same flux density distribution as the actual machine in no-load, is used to measure only the stator core loss. For this, a slip-ring rotor is designed and constructed. Furthermore, a modified calorimeter is constructed to accurately measure the stator core loss. In order to account only for the stator core loss, the test setup is excited from the stationary rotor which is also thermally isolated from the measurement chamber of the modified calorimeter. The experimental setup is then operated at various conditions to determine the range of operation having optimal accuracy. After that, the stator core losses at frequencies ranging from 300 Hz to 1 kHz and air-gap flux densities ranging from 0.3T to 0.4 T, are measured and compared with the results obtained from the FE simulation (FCSMEK). The measured result at almost all the frequencies and the air-gap flux densities is found to be approximately twice of that obtained from the FE simulation. Furthermore, the accuracy of measurement is acceptable for this comparison, but for future study, i.e. comparing the difference after the heat treatment, the level of inaccuracy is too high. Thus, few modifications are recommended.Item Coupled Magneto-Mechanical Analysis of Iron Sheets Under Biaxial Stress(Institute of Electrical & Electronics Engineers (IEEE), 2015) Aydin, Ugur; Rasilo, Paavo; Singh, Deepak; Lehikoinen, Antti; Belahcen, Anouar; Arkkio, Antero; Sähkötekniikan ja automaation laitos; Department of Electrical Engineering and Automation; Sähkötekniikan korkeakoulu; School of Electrical EngineeringA novel single sheet tester design is proposed and a directly coupled magneto-mechanical model is used to numerically analyze the behavior of iron sheets under biaxial magneto-mechanical loading applied by the tester device. magneto-mechanically coupled constitutive equations of the material derived using an energy-based approach are integrated into a finite element model of the single sheet tester device, and simulations are performed to solve for the displacement field and the magnetic vector potential in the sample. The obtained numerical results of magnetostriction evolution due to uniaxial stress and stress-induced anisotropies due to permeability variation under different magneto-mechanical loadings are presented. The simulation results are compared with the results published in the literature for the purpose of validation.Item Effect of Mechanical Stress on Excess Loss of Electrical Steel Sheets(IEEE, 2015) Singh, Deepak; Rasilo, Paavo; Martin, Floran; Belahcen, Anouar; Arkkio, Antero; Sähkötekniikan ja automaation laitos; Department of Electrical Engineering and Automation; Electromechanics; Sähkötekniikan korkeakoulu; School of Electrical EngineeringEffect of mechanical stress on the magnetic loss of electrical steel sheets is analyzed utilizing the statistical loss theory. The focus of the study is on the variation of the excess loss component with the applied stress and its correlation with the hysteresis loss. The model and its correlation are validated by performing comprehensive measurements at various combination of induction levels, frequencies and stresses. It is found that the excess losses can be modeled with sufficient accuracy by their correlation with the hysteresis losses over a wide range of stresses, frequencies and flux densities.Item Effect of Stress on Magnetic Properties of Electrical Steel Sheet and Core Losses in Electrical Machines(Aalto University, 2016) Singh, Deepak; Rasilo, Paavo, Asst. Prof., Tampere University of Technology, Tampere, Finland; Martin, Floran, Dr., Aalto University, Department of Electrical Engineering and Automation, Finland; Sähkötekniikan ja automaation laitos; Department of Electrical Engineering and Automation; Research Group of Electromechanics; Sähkötekniikan korkeakoulu; School of Electrical Engineering; Belahcen, Anouar, Prof., Aalto University, Electrical Machines, FinlandThis dissertation deals with the effect of stress on the magnetic properties of electrical steel sheets and, consequently, on the flux density distribution and the core loss of electrical machines. The stress effect on the permeability and the iron loss is measured using a modified single sheet tester, designed and custom built with the provision of unidirectional in-plane stressing. The measured stress dependent permeability and the developed stress dependent iron loss model are implemented in a 2D finite element (FE) machine model to investigate the effect of stress due to the shrink-fit, and the centrifugal forces on the flux and loss density distributions across the cross-section of the machine. From the simultaneous magnetic and magnetostriction measurements, a comprehensive stress dependent magnetostriction model has been proposed and later used in the magneto-mechanical coupling term of the well known Sablik-Jiles-Atherton static hysteresis model. Some modifications to the model parameters and the coupling term have been proposed to correctly model the BH-loop variation over a wide range of stress, both compressive and tensile. Similarly, the model parameters of the statistical iron loss model are made stress dependent, over a wide range of frequency, induction and stress, for further use in the estimation of the core losses. Finally, the measured permeability and the developed iron loss model, both stress dependent, are implemented in a 2D FE model of a synchronous reluctance machine. The stress distribution across the machine geometry is obtained from the static linear elasticity analysis for the shrink-fit and the rotation, and is coupled to the magnetic field formulation through the stress dependent permeability. The obtained magnetic field distribution is used in conjunction with the stress dependent iron loss model to post process for the core losses. The results obtained from the FE simulation with the inclusion of stress show a substantial difference in both the flux density distribution across the machine geometry and the loss density distribution across the stator core, when compared to the FE simulation result without the stress.Item Flexible identification procedure for thermodynamic constitutive models for magnetostrictive materials(ROYAL SOC, 2019-03-01) Rasilo, Paavo; Singh, Deepak; Jeronen, Juha; Aydin, Ugur; Martin, Floran; Belahcen, Anouar; Daniel, Laurent; Kouhia, Reijo; Department of Electrical Engineering and Automation; Tampere University; Université Paris-SudWe present a novel approach for identifying a multiaxial thermodynamic magneto-mechanical constitutive law by direct bi- or trivariate spline interpolation from available magnetization and magnetostriction data. Reference data are first produced with a multiscale model in the case of a magnetic field and uniaxial and shear stresses. The thermodynamic model fits well to the results of the multiscale model, after which the models are compared under complex multiaxial loadings. A surprisingly good agreement between the two models is found, but some differences in the magnetostrictive behaviour are also pointed out. Finally, the model is fitted to measurement results from an electrical steel sheet. The spline-based constitutive law overcomes several drawbacks of analytical approaches used earlier. The presented models and measurement results are openly available.Item In Plane Numerical Analysis of Mechanical Stress in a Synchronous Reluctance Machine(2013-08-30) Iruikwu, Daniel; Belahcen, Anouar; Singh, Deepak; Sähkötekniikan korkeakoulu; Arkkio, AnteroThe distortion due to the mechanical stresses from manufacturing issues and the operation of electrical machines are known to have adverse effect on the magnetic properties of electrical iron core and due to the stress dependency of iron core losses, it is therefore imperative that we account for the stresses from the different conditions causing mechanical stresses in a rotating electrical machine. This work presents a 2-D FE-analysis of the mechanical stresses due to shrink fitting, centrifugal forces and the magnetic forces in a 4-pole, 3-phase synchronous reluctance machine at rated frequency of 50 Hz. The stresses due to shrink fitting and centrifugal forces were computed by solid mechanics method, while the stresses due to magnetic forces were computed using both magnetic field method and solid mechanics method. The total mechanical stress distributions from all stress sources were obtained using a weakly coupled approach. It was found that shrink fitting causes a very large tensile stress at the rotor core and compressive stress in most part of the stator yoke, but have almost no effect at the stator teeth. The centrifugal forces also contribute to the total tensile stress of the rotor core. The magnetic forces have the least effect on the total stress distribution of the machine. The combined stresses obtained are mostly tensile at the rotor core and compressive at most part of the stator yoke, while the stator teeth were under low tensile stress due to the magnetic forces. The presence of flux barriers between flux paths at the rotor core causes large stresses to distribute at the bridge between flux barriers near the fit interface. Increase or decrease of the radial interference and/or frequency increases or reduces the total mechanical stress distribution of the machine.Item Magneto-Mechanical Model for Hysteresis in Electrical Steel Sheet(IEEE, 2016) Singh, Deepak; Martin, Floran; Rasilo, Paavo; Belachen, Anouar; Sähkötekniikan ja automaation laitos; Department of Electrical Engineering and Automation; Electromechanics; Sähkötekniikan korkeakoulu; School of Electrical EngineeringA coupled magneto-mechanical model for hysteresis in an electrical steel sheet is presented. The foundation of the model developed is the classical Sablik-Jiles-Atherton (SJA) model. A comprehensive model for the stress dependent magnetostriction is also proposed and implemented in the SJA model. Improvements in the SJA model as well, are proposed and validated with simultaneous measurements of magnetostriction, magnetic field and flux density. The measurements were performed on a single electrical steel sheet under various levels of stress (-35 MPa to 100 MPa). The proposed model was found to adequately model the permeability change and the local bowing of the BH-loop due to stress.Item Magneto-mechanical modeling of electrical steel sheets(Elsevier Science B.V., 2017-10-01) Aydin, Ugur; Rasilo, Paavo; Martin, Floran; Singh, Deepak; Daniel, Laurent; Belahcen, Anouar; Rekik, Mahmoud; Hubert, Olivier; Kouhia, Reijo; Arkkio, Antero; Department of Electrical Engineering and Automation; Computational Electromechanics; CentraleSupélec; Université Paris-Saclay; Tampere University of TechnologyA simplified multiscale approach and a Helmholtz free energy based approach for modeling the magneto-mechanical behavior of electrical steel sheets are compared. The models are identified from uniaxial magneto-mechanical measurements of two different electrical steel sheets which show different magneto-elastic behavior. Comparison with the available measurement data of the materials shows that both models successfully model the magneto-mechanical behavior of one of the studied materials, whereas for the second material only the Helmholtz free energy based approach is successful.Item A model for magneto-elastic behaviour(2017) Danaee, Siavash; Kouhia, Reijo; Rasilo, Paavo; Belahcen, Anouar; Singh, Deepak; Ristinmaa, Matti; Department of Electrical Engineering and Automation; Computational Electromechanics; Tampere University of Technology; Lund UniversityItem Model of Magnetic Anisotropy for Non-Oriented Steel Sheets for Finite Element Method(IEEE, 2016) Martin, Floran; Singh, Deepak; Rasilo, Paavo; Belahcen, Anouar; Arkkio, Antero; Sähkötekniikan ja automaation laitos; Department of Electrical Engineering and Automation; Sähkötekniikan korkeakoulu; School of Electrical EngineeringEven non-oriented steel sheets present a magnetic anisotropic behavior. From rotational flux density measurements at 5 Hz, the model of magnetic anisotropy is derived from two surface Basis-cubic splines with the boundary conditions matching with ferromagnetic theory. Furthermore, the investigation of the magnetic anisotropy shows that the H(B) characteristic is not strictly monotonous due to the angle difference between the field and the flux density. Hence, standard non-linear solvers would eitherdiverge or converge towards the closest local minimum. Thus, we propose two different specific solvers: a combined Particle Swarm Optimization with a relaxed Newton-Raphson and a Modified Newton Method.Item Modeling of Hysteresis Losses in Ferromagnetic Laminations under Mechanical Stress(Institute of Electrical & Electronics Engineers (IEEE), 2015) Rasilo, Paavo; Singh, Deepak; Aydin, Ugur; Martin, Floran; Kouhia, Reijo; Belahcen, Anouar; Arkkio, Antero; Sähkötekniikan ja automaation laitos; Department of Electrical Engineering and Automation; Sähkötekniikan korkeakoulu; School of Electrical EngineeringA novel approach for predicting magnetic hysteresis loops and losses in ferromagnetic laminations under mechanical stress is presented. The model is based on combining a Helmholtz free energy -based anhysteretic magnetoelastic constitutive law to a vector Jiles-Atherton hysteresis model. This paper focuses only on unidirectional and parallel magnetic fields and stresses, albeit the model is developed in full 3-D configuration in order to account also for strains perpendicular to the loading direction. The model parameters are fitted to magnetization curve measurements under compressive and tensile stresses. Both the hysteresis loops and losses are modeled accurately for stresses ranging from –50 to 80 MPa.Item Modeling the stress effect on the measurement of magnetostriction in electrical sheets under rotational magnetization(2018-08-16) Belahcen, Anouar; Rasilo, Paavo; Fonteyn, Katarzyna; Kouhia, Reijo; Singh, Deepak; Arkkio, Antero; Department of Electrical Engineering and Automation; Computational ElectromechanicsThe magnetostriction in electrical steel under rotational magnetization is usually measured with cross-shaped samples. However, the inhomogeneity of the magnetization and stress in the sample might hinder the measured results. In this paper, we investigate this phenomenon by using a magneto-mechanically coupled energy-based model to simulate the sample in a single sheet tester measurement setup, and compare the simulations and measurements. The results show that some anomalies in the measured magnetostriction can be explained by the inhomogeneous magnetization in the sample and the form effect, which result in inhomogeneous stresses and thus affect the observed quantities. The validity of the model as well as the presented statements are ascertained through experiments on the single sheet tester. The backgrounds of the used modelization technique are also detailed.Item Preliminary results on the effect of plastic deformation on magnetic properties(2017) Singh, Deepak; Mökkönen, Kati; Poutala, Jarmo; Rasilo, Paavo; Belahcen, Anouar; Kouhia, Reijo; Department of Electrical Engineering and Automation; Computational Electromechanics; Tampere University of TechnologyIn this paper some preliminary results on the effect of plastic deformation on magnetic properties of an electric steel are presented. Both experimental results and modelling aspects are discussed.