M. Chiampi - Academia.edu (original) (raw)
Papers by M. Chiampi
2005 5th IEEE International Symposium on Diagnostics for Electric Machines, Power Electronics and Drives, 2005
Diagnostic techniques for induction machines based on the motor current signature analysis monito... more Diagnostic techniques for induction machines based on the motor current signature analysis monitor the increase of specific frequencies of the stator current spectrum, that are directly linked to anomalous conditions. The stator current spectrum includes several lines, that need to be accurately analyzed in order to achieve a reliable fault diagnosis. Several papers in the literature deal with the analysis of stator currents lines, while it is hard to retrieve information on rotor cage variables. In this paper a dedicated induction machine and experimental set-up developed at IEN is used, that allows the acquisition of instantaneous bar currents, through current sensors mounted on the rotor bars. Though artificial faults are not introduced in the machine, intrinsic non-idealities introduce harmonic distortion in the machine variables. Rotor instantaneous currents are computed by finite element approach and the results are compared with the experimental ones. Then the FFT algorithm is applied to scalar and complex variables and the results are analyzed with the help of the rotating field approach. Reference is made to synchronous operating conditions in order to address the rotor current components caused only by non-idealities.
INTERMAG 2006 - IEEE International Magnetics Conference, 2006
ABSTRACT
Journal of Magnetism and Magnetic Materials, 2000
The paper presents a two-dimensional numerical model, based on the "nite element method, for the ... more The paper presents a two-dimensional numerical model, based on the "nite element method, for the analysis of the electromagnetic "eld inside narrow ferromagnetic strips, including hysteresis behaviour. The e!ect of the ratio between width and thickness of the sheet is analysed for stated supply conditions and the results are compared with the ones provided by a one-dimensional model, previously developed by the authors.
Journal of Applied Physics, 2008
In this paper magnetostrictive rods are analyzed coupling a magnetoelastic model of Terfenol-D ro... more In this paper magnetostrictive rods are analyzed coupling a magnetoelastic model of Terfenol-D rods based on Preisach theory with a finite element electromagnetic field solution, accounting for dynamic effects within the rod. The computed results, compared with experiments, evidence the influence of eddy currents and magnetization dynamic on the magnetostrictive rod behavior.
IEE Proceedings - Generation, Transmission and Distribution, 2001
Shielding of magnetic fields at power frequencies has been investigated by computation and experi... more Shielding of magnetic fields at power frequencies has been investigated by computation and experiment. Different types of low-cost soff magnetic laminations (low-carbon steel, nonoriented FeSi, grain-oriented Fe-Si) and different shield geometries (plane, U-shaped and box-like) have been considered. The shielding factors of model screens have been measured, together with the magnetic flux density in the sheets employed, under field levels typical of industrial environment (-lOOpT). Computations have been carried out by means of a hybrid finite-elementboundary element model, which result in good agreement with measurements. It is shown that grain-oriented laminations provide the highest shielding factor, which is reinforced in the plane shield configuration by the addition of an aluminium plate. it is predicted that the screening performance of the U-shaped and box-like shields can be appreciably impaired by the presence of air gaps at the corner joints.
IEEE Transactions on Magnetics, 1985
A computational procedure is developed to analyze two-dimensional nonlinear electromagnetic field... more A computational procedure is developed to analyze two-dimensional nonlinear electromagnetic fields in steady-state alternating conditions both when the currents in the conductors are specified and when the voltage sources and the electrical connections are assigned; furthermore the effects of eddy currents can be included. In every case the finite element and Fourier approximations and the iterative method employed to handle magnetic nonlinearities lead to a set of linear algebraic systems having the same block structure. The application of the procedure 1s illustrated by analyzing a no-load threephase transformer neglecting eddy currents and a high-frequency single-phase transformer including the skin effect.
IEEE Transactions on Magnetics, 1995
IEEE Transactions on Magnetics, 2006
This paper deals with the performances of high-speed induction motors for turbo-molecular pump ap... more This paper deals with the performances of high-speed induction motors for turbo-molecular pump applications. A comparison between squirrel-cage and drag-cup motors is performed by a modeling and experimental analysis. Possible improvements to increase the drag-cup motor efficiency and to reduce rotor losses are investigated acting on the rotor design.
IEEE Transactions on Magnetics, 2005
A mathematical homogenization technique is applied to the computation of eddy currents in strip-w... more A mathematical homogenization technique is applied to the computation of eddy currents in strip-wound amorphous cores. The results are compared with a standard finite-element (FE) solution of a test problem. The method is applied to the analysis of an amorphous core in a frequency range up to 1 MHz, with main emphasis on energy loss prediction.
IEE Proceedings - Science, Measurement and Technology, 2004
ABSTRACT
Journal of Magnetism and Magnetic Materials, 1994
This paper investigates different iterative techniques (direct iteration, Newton-Raphson and fixe... more This paper investigates different iterative techniques (direct iteration, Newton-Raphson and fixed point methods) for the solution of nonlinear magnetic problems neglecting hysteresis. The investigations are carried out on a one-dimensional model problem whose exact nonlinear solution is computed when the magnetic flux is assigned. In spite of its simplicity, this model can present the same computational difficulties as most actual
IEEE Transactions on Instrumentation and Measurement, 2007
This paper describes the design process, the specific features, and the characterization procedur... more This paper describes the design process, the specific features, and the characterization procedures of the Istituto Nazionale di Ricerca Metrologica (I.N.RI.M.) set up for the generation of reference magnetic fields in the frequency range from 1 to 100 kHz. Numerical techniques, validated by comparison with experimental data, make it possible to choose the best solutions for obtaining magnetic flux densities up to 100 µT at 1 kHz and 25 µT at 100 kHz with relative uncertainty from a few parts in 10 3 up to the percent.
Applied Mathematical Modelling, 2008
The electromagnetic diffusion and the electromechanical phenomena arising in a solid cylinder rot... more The electromagnetic diffusion and the electromechanical phenomena arising in a solid cylinder rotating inside a magnetic field are here analyzed. The study is developed through a time stepping Finite Element voltage-driven formulation, employing the sliding mesh technique for handling the cylinder motion. The influence on the dynamic behavior and energy dissipation of the material electric and magnetic properties, the geometrical parameters and the supply conditions is investigated considering a model problem.
IEEE Transactions on Magnetics, 1980
The author is indebted to C. W. Steele for many helpful discussions. [7] D. A. Lindholm, "Seconda... more The author is indebted to C. W. Steele for many helpful discussions. [7] D. A. Lindholm, "Secondary gap effect in narrow and wide track reproduce heads," IEEE
IEEE Transactions on Magnetics, 2009
Contactless electromagnetic temperature sensors are analyzed and compared, under a number of conf... more Contactless electromagnetic temperature sensors are analyzed and compared, under a number of configurations, for applications in spinning devices. Their working principle is based on the variation of electrical or magnetic properties with temperature. By a preliminary study, carried out through finite element modeling, a number of effective solutions have been identified and a few of them have then been selected for testing in the laboratory. Two significant experimental examples are here discussed.
IEEE Transactions on Magnetics, 1981
Previously, a successive approximations procedure was developed to compute by means of the f f i ... more Previously, a successive approximations procedure was developed to compute by means of the f f i t e element method the magnetic field in nonhomogeneous nonlinear media. This method is now extended to multiply connected domains with boundary conditions well suited to the study of power transformer cores. Essential features of the present approach are a consistent use of integral constraints in the variational formulation of the problem and a full exploitation of the space and time symmetries involved. Some numerical results for twwiimensional problems are discussed in the last sections.
IEEE Transactions on Magnetics, 1980
The author is indebted to C. W. Steele for many helpful discussions. [7] D. A. Lindholm, "Seconda... more The author is indebted to C. W. Steele for many helpful discussions. [7] D. A. Lindholm, "Secondary gap effect in narrow and wide track reproduce heads," IEEE
IEEE Transactions on Magnetics, 2012
This paper presents the application of a finite element multiscale method, based on the homogeniz... more This paper presents the application of a finite element multiscale method, based on the homogenization technique, to the prediction 11 of classical losses in soft magnetic composite materials. The experimental results, obtained for a wide range of frequencies and for 12 various toroidal samples with different cross sections, are explained by using the considered model. It has been found that the classical 13 losses are influenced by the dimensions of the sample, as well as by the conductivity and the length of the random contacts between the 14 grains.
... Phys. J. Appl. Phys. 30, 716 (2005) DOI: 10.1051/epjap:2005009 THE EUROPEAN PHYSICAL JOURNAL... more ... Phys. J. Appl. Phys. 30, 716 (2005) DOI: 10.1051/epjap:2005009 THE EUROPEAN PHYSICAL JOURNAL APPLIED PHYSICS Prediction of losses in induction machines: a challenge for the modelling approaches O. Bottauscio 1,a , M. Chiampi 2 , A. Manzin 1 , and M. Zucca 1 ...
2005 5th IEEE International Symposium on Diagnostics for Electric Machines, Power Electronics and Drives, 2005
Diagnostic techniques for induction machines based on the motor current signature analysis monito... more Diagnostic techniques for induction machines based on the motor current signature analysis monitor the increase of specific frequencies of the stator current spectrum, that are directly linked to anomalous conditions. The stator current spectrum includes several lines, that need to be accurately analyzed in order to achieve a reliable fault diagnosis. Several papers in the literature deal with the analysis of stator currents lines, while it is hard to retrieve information on rotor cage variables. In this paper a dedicated induction machine and experimental set-up developed at IEN is used, that allows the acquisition of instantaneous bar currents, through current sensors mounted on the rotor bars. Though artificial faults are not introduced in the machine, intrinsic non-idealities introduce harmonic distortion in the machine variables. Rotor instantaneous currents are computed by finite element approach and the results are compared with the experimental ones. Then the FFT algorithm is applied to scalar and complex variables and the results are analyzed with the help of the rotating field approach. Reference is made to synchronous operating conditions in order to address the rotor current components caused only by non-idealities.
INTERMAG 2006 - IEEE International Magnetics Conference, 2006
ABSTRACT
Journal of Magnetism and Magnetic Materials, 2000
The paper presents a two-dimensional numerical model, based on the "nite element method, for the ... more The paper presents a two-dimensional numerical model, based on the "nite element method, for the analysis of the electromagnetic "eld inside narrow ferromagnetic strips, including hysteresis behaviour. The e!ect of the ratio between width and thickness of the sheet is analysed for stated supply conditions and the results are compared with the ones provided by a one-dimensional model, previously developed by the authors.
Journal of Applied Physics, 2008
In this paper magnetostrictive rods are analyzed coupling a magnetoelastic model of Terfenol-D ro... more In this paper magnetostrictive rods are analyzed coupling a magnetoelastic model of Terfenol-D rods based on Preisach theory with a finite element electromagnetic field solution, accounting for dynamic effects within the rod. The computed results, compared with experiments, evidence the influence of eddy currents and magnetization dynamic on the magnetostrictive rod behavior.
IEE Proceedings - Generation, Transmission and Distribution, 2001
Shielding of magnetic fields at power frequencies has been investigated by computation and experi... more Shielding of magnetic fields at power frequencies has been investigated by computation and experiment. Different types of low-cost soff magnetic laminations (low-carbon steel, nonoriented FeSi, grain-oriented Fe-Si) and different shield geometries (plane, U-shaped and box-like) have been considered. The shielding factors of model screens have been measured, together with the magnetic flux density in the sheets employed, under field levels typical of industrial environment (-lOOpT). Computations have been carried out by means of a hybrid finite-elementboundary element model, which result in good agreement with measurements. It is shown that grain-oriented laminations provide the highest shielding factor, which is reinforced in the plane shield configuration by the addition of an aluminium plate. it is predicted that the screening performance of the U-shaped and box-like shields can be appreciably impaired by the presence of air gaps at the corner joints.
IEEE Transactions on Magnetics, 1985
A computational procedure is developed to analyze two-dimensional nonlinear electromagnetic field... more A computational procedure is developed to analyze two-dimensional nonlinear electromagnetic fields in steady-state alternating conditions both when the currents in the conductors are specified and when the voltage sources and the electrical connections are assigned; furthermore the effects of eddy currents can be included. In every case the finite element and Fourier approximations and the iterative method employed to handle magnetic nonlinearities lead to a set of linear algebraic systems having the same block structure. The application of the procedure 1s illustrated by analyzing a no-load threephase transformer neglecting eddy currents and a high-frequency single-phase transformer including the skin effect.
IEEE Transactions on Magnetics, 1995
IEEE Transactions on Magnetics, 2006
This paper deals with the performances of high-speed induction motors for turbo-molecular pump ap... more This paper deals with the performances of high-speed induction motors for turbo-molecular pump applications. A comparison between squirrel-cage and drag-cup motors is performed by a modeling and experimental analysis. Possible improvements to increase the drag-cup motor efficiency and to reduce rotor losses are investigated acting on the rotor design.
IEEE Transactions on Magnetics, 2005
A mathematical homogenization technique is applied to the computation of eddy currents in strip-w... more A mathematical homogenization technique is applied to the computation of eddy currents in strip-wound amorphous cores. The results are compared with a standard finite-element (FE) solution of a test problem. The method is applied to the analysis of an amorphous core in a frequency range up to 1 MHz, with main emphasis on energy loss prediction.
IEE Proceedings - Science, Measurement and Technology, 2004
ABSTRACT
Journal of Magnetism and Magnetic Materials, 1994
This paper investigates different iterative techniques (direct iteration, Newton-Raphson and fixe... more This paper investigates different iterative techniques (direct iteration, Newton-Raphson and fixed point methods) for the solution of nonlinear magnetic problems neglecting hysteresis. The investigations are carried out on a one-dimensional model problem whose exact nonlinear solution is computed when the magnetic flux is assigned. In spite of its simplicity, this model can present the same computational difficulties as most actual
IEEE Transactions on Instrumentation and Measurement, 2007
This paper describes the design process, the specific features, and the characterization procedur... more This paper describes the design process, the specific features, and the characterization procedures of the Istituto Nazionale di Ricerca Metrologica (I.N.RI.M.) set up for the generation of reference magnetic fields in the frequency range from 1 to 100 kHz. Numerical techniques, validated by comparison with experimental data, make it possible to choose the best solutions for obtaining magnetic flux densities up to 100 µT at 1 kHz and 25 µT at 100 kHz with relative uncertainty from a few parts in 10 3 up to the percent.
Applied Mathematical Modelling, 2008
The electromagnetic diffusion and the electromechanical phenomena arising in a solid cylinder rot... more The electromagnetic diffusion and the electromechanical phenomena arising in a solid cylinder rotating inside a magnetic field are here analyzed. The study is developed through a time stepping Finite Element voltage-driven formulation, employing the sliding mesh technique for handling the cylinder motion. The influence on the dynamic behavior and energy dissipation of the material electric and magnetic properties, the geometrical parameters and the supply conditions is investigated considering a model problem.
IEEE Transactions on Magnetics, 1980
The author is indebted to C. W. Steele for many helpful discussions. [7] D. A. Lindholm, "Seconda... more The author is indebted to C. W. Steele for many helpful discussions. [7] D. A. Lindholm, "Secondary gap effect in narrow and wide track reproduce heads," IEEE
IEEE Transactions on Magnetics, 2009
Contactless electromagnetic temperature sensors are analyzed and compared, under a number of conf... more Contactless electromagnetic temperature sensors are analyzed and compared, under a number of configurations, for applications in spinning devices. Their working principle is based on the variation of electrical or magnetic properties with temperature. By a preliminary study, carried out through finite element modeling, a number of effective solutions have been identified and a few of them have then been selected for testing in the laboratory. Two significant experimental examples are here discussed.
IEEE Transactions on Magnetics, 1981
Previously, a successive approximations procedure was developed to compute by means of the f f i ... more Previously, a successive approximations procedure was developed to compute by means of the f f i t e element method the magnetic field in nonhomogeneous nonlinear media. This method is now extended to multiply connected domains with boundary conditions well suited to the study of power transformer cores. Essential features of the present approach are a consistent use of integral constraints in the variational formulation of the problem and a full exploitation of the space and time symmetries involved. Some numerical results for twwiimensional problems are discussed in the last sections.
IEEE Transactions on Magnetics, 1980
The author is indebted to C. W. Steele for many helpful discussions. [7] D. A. Lindholm, "Seconda... more The author is indebted to C. W. Steele for many helpful discussions. [7] D. A. Lindholm, "Secondary gap effect in narrow and wide track reproduce heads," IEEE
IEEE Transactions on Magnetics, 2012
This paper presents the application of a finite element multiscale method, based on the homogeniz... more This paper presents the application of a finite element multiscale method, based on the homogenization technique, to the prediction 11 of classical losses in soft magnetic composite materials. The experimental results, obtained for a wide range of frequencies and for 12 various toroidal samples with different cross sections, are explained by using the considered model. It has been found that the classical 13 losses are influenced by the dimensions of the sample, as well as by the conductivity and the length of the random contacts between the 14 grains.
... Phys. J. Appl. Phys. 30, 716 (2005) DOI: 10.1051/epjap:2005009 THE EUROPEAN PHYSICAL JOURNAL... more ... Phys. J. Appl. Phys. 30, 716 (2005) DOI: 10.1051/epjap:2005009 THE EUROPEAN PHYSICAL JOURNAL APPLIED PHYSICS Prediction of losses in induction machines: a challenge for the modelling approaches O. Bottauscio 1,a , M. Chiampi 2 , A. Manzin 1 , and M. Zucca 1 ...