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Papers by Virgiliu Fireteanu

Research paper thumbnail of Mathematical modelling of interaction between electromagnetic and thermal fields in submerged-electrode furnaces

Research paper thumbnail of Electromagnetic pumping in the channel induction furnace

Determination des champs magnetiques de l'induction et de la bobine de pompage dans la zone d... more Determination des champs magnetiques de l'induction et de la bobine de pompage dans la zone du canal de pompage d'un nouveau type de four a induction a vidage par pompage electromagnetique. Calcul de la repartition de la densite du courant dans le canal, de la densite de la force electromagnetique et de la pression de pompage

Research paper thumbnail of Finite Element 2D and 3D Models of a Rotor Bar Breakage in a Squirrel-Cage Induction Motor

2019 IEEE Workshop on Electrical Machines Design, Control and Diagnosis (WEMDCD), 2019

Frequency domain and step by step in time domain finite element analyses of the electromagnetic f... more Frequency domain and step by step in time domain finite element analyses of the electromagnetic field in a squirrel cage inductor motor are considered for different 2D and 3D models of a rotor bar breakage process and of the end of this process – the broken bar fault.The faulty operation states of a rotor squirrel cage are correctly reflected only by the 3D models. However, there are cases when 2D approximate models, much more advantageous related the computation time and memory requirements can offer satisfactory results. Comparing 2D and 3D results, this paper shows in case of a rotor bar breakage when the option for a 2D model instead the 3D model can be accepted.

Research paper thumbnail of Influence of Single or Multiple Faults Short-circuit, Broken Rotor Bar and Eccentricity on the Torque and Rotor Force in Induction Motors

2018 XIII International Conference on Electrical Machines (ICEM), 2018

Based on finite element analysis in time domain of a squirrel cage induction motor, this paper st... more Based on finite element analysis in time domain of a squirrel cage induction motor, this paper studies the influence of the three faults - stator short-circuit, broken rotor bar and static eccentricity, on the mean values and on the harmonics of motor torque and unbalanced rotor force. Results for healthy motor operation and for seven faulty cases, with single, double and triple faults, are evaluated and compared. The influence of the broken bar fault on the motor torque, single or in combination with the short-circuit fault or/and with the eccentricity, is much more important than the influence of the other two faults. Related to the rotor unbalanced force, all faulty cases are characterized by important or very important increase of this force compared with the healthy case.

Research paper thumbnail of Simultaneous Induction Heating and Electromagnetic Stirring of a Molten Glass Bath

This paper studies solutions for an efficient induction heating and a strong electromagnetic stir... more This paper studies solutions for an efficient induction heating and a strong electromagnetic stirring of the molten glass bath through the action of Lorentz forces in a direct induction furnace. Different spatial configurations of AC magnetic fields - travelling, rotating or helicoidal, and the generated molten glass electromagnetic stirring are studied with one-way coupled electromagnetic and hydrodynamic models. For imposed value of the active power induced in the molten glass, the numerical experiments offers the values of the total inductor current and of the supply frequency for which an efficient electromagnetic stirring of molten glass is achieved.

Research paper thumbnail of Electromagnetic Forming - an Efficient Technology for Metallic Sheet Processing

Przegląd Elektrotechniczny, 2008

Research paper thumbnail of Finite element analysis of electromagnetic transient in magneto-forming processes

Archives of Electrical Engineering, 2005

Research paper thumbnail of Coupled Field-Circuit Finite Element Models of a Cold Crucible Furnace in its Environment

Based on dedicated coupled field-circuit models, this paper investigates important parameters of ... more Based on dedicated coupled field-circuit models, this paper investigates important parameters of a 300 kHz cold crucible induction furnace in its environment, where metallic water cooling pipes and protective components are present. The finite element computation uses the 3D scalar model of the electromagnetic field and the surface impedance model of the solid conductor regions. The current density, the associated losses, voltages between different parts of the furnace and electrical currents circulating through the pipes are evaluated.

Research paper thumbnail of Optimal parameters of the three-phase inductor with travelling field for electromagnetic stirring

Research paper thumbnail of Finite element analysis of an eddy currents heater for wind or water kinetic energy conversion into heat

Renewable Energy and Power Quality Journal, 2010

The paper presents 2D and 3D finite element models for the analysis of the electromagnetic and th... more The paper presents 2D and 3D finite element models for the analysis of the electromagnetic and thermal fields and the local and global quantities in an eddy current heater with permanent magnets, able to convert the wind or water kinetic energy into heat. Correlations between the input and output operational parameters of the heater are studied taking into account the temperature dependence of physical properties and the magnetic nonlinearity.

Research paper thumbnail of Teaching synchronous machines by finite element models

2008 11th International Conference on Optimization of Electrical and Electronic Equipment, 2008

This paper deals with an educational experiment of teaching basic knowledge on electromagnetic st... more This paper deals with an educational experiment of teaching basic knowledge on electromagnetic structure of synchronous electrical machines, standard operation and testing and parameters evaluation based on finite element models and analyses.

Research paper thumbnail of 3D Magneto-Thermal Computations in Induction Heating. Models and Experimental Validations

Research paper thumbnail of Field-circuit-motion numerical models of the AC tachogenerator with rotor of solid conductor type

2007 IEEE International Electric Machines & Drives Conference, 2007

The paper deals with the finite element analysis of a simple and reliable speed transducer - the ... more The paper deals with the finite element analysis of a simple and reliable speed transducer - the AC tachogenerator with rotor of solid conductor type. The coupling between the field equations, circuit equations and the rotor motion is considered in the numerical computation of eddy currents and global quantities that characterize the transducer operation. The diffusion of the electromagnetic field in the rotor, the speed - output voltage dependence, the power losses in the rotor and the power delivered by the 50 Hz supply source to the field winding of the transducer are evaluated for three rotor types: homogeneous copper or magnetic nonlinear steel rotors and a rotor consisting in a copper cup around a magnetic steel cylinder. The sensitivity of the transducer output voltage with respect the magnetic properties of the rotor and the airgap value is analyzed. The linearity of the output voltage - speed characteristic of the tachogenerator when the field winding is 400 Hz supplied and the upper limit of speed measurement is very low in comparison with the synchronous speed is studied.

Research paper thumbnail of Magneto-Thermal-Translating Motion Coupling in 3D Finite Element Analysis of Metallic Sheets Transverse Flux Induction Heating

This paper deals with the 3D finite element analysis of metallic sheets heating in translating mo... more This paper deals with the 3D finite element analysis of metallic sheets heating in translating motion through the airgap of an inductor of transverse flux type. This study presents two different magneto - thermal - translating motion coupling techniques used to analyze the transient temperature field of the metallic sheets characterized by given electromagnetic and thermal properties. A solution to improve the transversal thermal profile of the metallic sheet based on the magnetic shielding is proposed and analyzed. The numerical results of the thermal field are validated by experimental measurements.

Research paper thumbnail of Simulation-Driven Design and Optimization of a New Two-Coil Crucible Induction Furnace Using the Altair FLUX3D® Software

Innovations, 2019

A new two-coil crucible induction furnace with a lateral coil connected to the one-phase electric... more A new two-coil crucible induction furnace with a lateral coil connected to the one-phase electric power supply and a bottom coil connected to a capacitor bank with an appropriate value of the capacity is able to realize a desired balance between the induction heating of the lateral face and of the bottom face of the furnace bath. The evaluation of the optimum value of the capacity, which corresponds to the same mean value of the induced power density on the respective faces, represents an example of simulation-driven optimal design. Finite element models are used to study many variants of the new furnace related the number of turns of the two coils and related the diameter of the furnace bath for imposed bath volume.

Research paper thumbnail of Finite Element Analysis of a New Furnace with Travelling Field Inductor for Induction Heating, Electromagnetic Stirring and Levitation of Molten Titanium Alloys

The study based on finite element (FE) models of the electromagnetic field and of the motion insi... more The study based on finite element (FE) models of the electromagnetic field and of the motion inside the volume of the levitated molten titanium alloy of a new induction furnace equipped with a travelling field inductor in this paper is focused on three important effects-induction heating, electromagnetic stirring and charge levitation. The main parameters of this study are the charge weight, the supply frequency and the relative position charge-inductor.

Research paper thumbnail of 3D magneto-thermal computations of electromagnetic induction phenomena

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, 2003

ABSTRACT This paper presents the results of a series of tests made in order to validate the magne... more ABSTRACT This paper presents the results of a series of tests made in order to validate the magneto-thermal module of the new FLUX3D v3.40. The tool was conceived to solve the coupled problems of electromagnetic and thermal phenomena. The solving method of the program considers a thermal-transient problem during a certain period of time and it solves, at each time step, the thermal and electromagnetic equations (in quasi-stationary magneto-harmonic formulation), alternatively. We have modelled the inductive longitudinal welding of steel pipes. The results of 3D simulations are compared with measurements on a laboratory device.

Research paper thumbnail of Finite Element Analysis of Cold Crucible Configurations for Efficient Induction Heating of a Large Range of Molten Glass Volumes with the Same Inductor and Electric Supply

Conference OPTIM-ACEMP 2021, 2021

Based on finite element models, this paper investigates different cold crucible configurations fo... more Based on finite element models, this paper investigates different cold crucible configurations for efficient induction heating of molten glass charges with volumes in a large range by using a unique inductor and electric supply. The performances of cold crucible induction furnaces with a new one-segment annular cold crucibles for molten glass charges with diameter independent on the charge volume or for charges that conserves the ratio charge diameter / height are compared with those of the usual furnace with multi-segment round tubes cold crucible. Keywords-cold crucible induction furnace; 3D finite element models, segmented annular cold crucibles, large range of molten glasses heated volumes I.

Research paper thumbnail of Finite Element Analysis of Cold Crucible Configurations for Efficient Induction Heating of a Large Range of Molten Glass Volumes with the Same Inductor and Electric Supply

2021 International Aegean Conference on Electrical Machines and Power Electronics (ACEMP) & 2021 International Conference on Optimization of Electrical and Electronic Equipment (OPTIM)

Research paper thumbnail of Influences on the electromagnetic torque and rotor force of different faults in squirrel-cage induction motors

International Journal of Applied Electromagnetics and Mechanics

Research paper thumbnail of Mathematical modelling of interaction between electromagnetic and thermal fields in submerged-electrode furnaces

Research paper thumbnail of Electromagnetic pumping in the channel induction furnace

Determination des champs magnetiques de l'induction et de la bobine de pompage dans la zone d... more Determination des champs magnetiques de l'induction et de la bobine de pompage dans la zone du canal de pompage d'un nouveau type de four a induction a vidage par pompage electromagnetique. Calcul de la repartition de la densite du courant dans le canal, de la densite de la force electromagnetique et de la pression de pompage

Research paper thumbnail of Finite Element 2D and 3D Models of a Rotor Bar Breakage in a Squirrel-Cage Induction Motor

2019 IEEE Workshop on Electrical Machines Design, Control and Diagnosis (WEMDCD), 2019

Frequency domain and step by step in time domain finite element analyses of the electromagnetic f... more Frequency domain and step by step in time domain finite element analyses of the electromagnetic field in a squirrel cage inductor motor are considered for different 2D and 3D models of a rotor bar breakage process and of the end of this process – the broken bar fault.The faulty operation states of a rotor squirrel cage are correctly reflected only by the 3D models. However, there are cases when 2D approximate models, much more advantageous related the computation time and memory requirements can offer satisfactory results. Comparing 2D and 3D results, this paper shows in case of a rotor bar breakage when the option for a 2D model instead the 3D model can be accepted.

Research paper thumbnail of Influence of Single or Multiple Faults Short-circuit, Broken Rotor Bar and Eccentricity on the Torque and Rotor Force in Induction Motors

2018 XIII International Conference on Electrical Machines (ICEM), 2018

Based on finite element analysis in time domain of a squirrel cage induction motor, this paper st... more Based on finite element analysis in time domain of a squirrel cage induction motor, this paper studies the influence of the three faults - stator short-circuit, broken rotor bar and static eccentricity, on the mean values and on the harmonics of motor torque and unbalanced rotor force. Results for healthy motor operation and for seven faulty cases, with single, double and triple faults, are evaluated and compared. The influence of the broken bar fault on the motor torque, single or in combination with the short-circuit fault or/and with the eccentricity, is much more important than the influence of the other two faults. Related to the rotor unbalanced force, all faulty cases are characterized by important or very important increase of this force compared with the healthy case.

Research paper thumbnail of Simultaneous Induction Heating and Electromagnetic Stirring of a Molten Glass Bath

This paper studies solutions for an efficient induction heating and a strong electromagnetic stir... more This paper studies solutions for an efficient induction heating and a strong electromagnetic stirring of the molten glass bath through the action of Lorentz forces in a direct induction furnace. Different spatial configurations of AC magnetic fields - travelling, rotating or helicoidal, and the generated molten glass electromagnetic stirring are studied with one-way coupled electromagnetic and hydrodynamic models. For imposed value of the active power induced in the molten glass, the numerical experiments offers the values of the total inductor current and of the supply frequency for which an efficient electromagnetic stirring of molten glass is achieved.

Research paper thumbnail of Electromagnetic Forming - an Efficient Technology for Metallic Sheet Processing

Przegląd Elektrotechniczny, 2008

Research paper thumbnail of Finite element analysis of electromagnetic transient in magneto-forming processes

Archives of Electrical Engineering, 2005

Research paper thumbnail of Coupled Field-Circuit Finite Element Models of a Cold Crucible Furnace in its Environment

Based on dedicated coupled field-circuit models, this paper investigates important parameters of ... more Based on dedicated coupled field-circuit models, this paper investigates important parameters of a 300 kHz cold crucible induction furnace in its environment, where metallic water cooling pipes and protective components are present. The finite element computation uses the 3D scalar model of the electromagnetic field and the surface impedance model of the solid conductor regions. The current density, the associated losses, voltages between different parts of the furnace and electrical currents circulating through the pipes are evaluated.

Research paper thumbnail of Optimal parameters of the three-phase inductor with travelling field for electromagnetic stirring

Research paper thumbnail of Finite element analysis of an eddy currents heater for wind or water kinetic energy conversion into heat

Renewable Energy and Power Quality Journal, 2010

The paper presents 2D and 3D finite element models for the analysis of the electromagnetic and th... more The paper presents 2D and 3D finite element models for the analysis of the electromagnetic and thermal fields and the local and global quantities in an eddy current heater with permanent magnets, able to convert the wind or water kinetic energy into heat. Correlations between the input and output operational parameters of the heater are studied taking into account the temperature dependence of physical properties and the magnetic nonlinearity.

Research paper thumbnail of Teaching synchronous machines by finite element models

2008 11th International Conference on Optimization of Electrical and Electronic Equipment, 2008

This paper deals with an educational experiment of teaching basic knowledge on electromagnetic st... more This paper deals with an educational experiment of teaching basic knowledge on electromagnetic structure of synchronous electrical machines, standard operation and testing and parameters evaluation based on finite element models and analyses.

Research paper thumbnail of 3D Magneto-Thermal Computations in Induction Heating. Models and Experimental Validations

Research paper thumbnail of Field-circuit-motion numerical models of the AC tachogenerator with rotor of solid conductor type

2007 IEEE International Electric Machines & Drives Conference, 2007

The paper deals with the finite element analysis of a simple and reliable speed transducer - the ... more The paper deals with the finite element analysis of a simple and reliable speed transducer - the AC tachogenerator with rotor of solid conductor type. The coupling between the field equations, circuit equations and the rotor motion is considered in the numerical computation of eddy currents and global quantities that characterize the transducer operation. The diffusion of the electromagnetic field in the rotor, the speed - output voltage dependence, the power losses in the rotor and the power delivered by the 50 Hz supply source to the field winding of the transducer are evaluated for three rotor types: homogeneous copper or magnetic nonlinear steel rotors and a rotor consisting in a copper cup around a magnetic steel cylinder. The sensitivity of the transducer output voltage with respect the magnetic properties of the rotor and the airgap value is analyzed. The linearity of the output voltage - speed characteristic of the tachogenerator when the field winding is 400 Hz supplied and the upper limit of speed measurement is very low in comparison with the synchronous speed is studied.

Research paper thumbnail of Magneto-Thermal-Translating Motion Coupling in 3D Finite Element Analysis of Metallic Sheets Transverse Flux Induction Heating

This paper deals with the 3D finite element analysis of metallic sheets heating in translating mo... more This paper deals with the 3D finite element analysis of metallic sheets heating in translating motion through the airgap of an inductor of transverse flux type. This study presents two different magneto - thermal - translating motion coupling techniques used to analyze the transient temperature field of the metallic sheets characterized by given electromagnetic and thermal properties. A solution to improve the transversal thermal profile of the metallic sheet based on the magnetic shielding is proposed and analyzed. The numerical results of the thermal field are validated by experimental measurements.

Research paper thumbnail of Simulation-Driven Design and Optimization of a New Two-Coil Crucible Induction Furnace Using the Altair FLUX3D® Software

Innovations, 2019

A new two-coil crucible induction furnace with a lateral coil connected to the one-phase electric... more A new two-coil crucible induction furnace with a lateral coil connected to the one-phase electric power supply and a bottom coil connected to a capacitor bank with an appropriate value of the capacity is able to realize a desired balance between the induction heating of the lateral face and of the bottom face of the furnace bath. The evaluation of the optimum value of the capacity, which corresponds to the same mean value of the induced power density on the respective faces, represents an example of simulation-driven optimal design. Finite element models are used to study many variants of the new furnace related the number of turns of the two coils and related the diameter of the furnace bath for imposed bath volume.

Research paper thumbnail of Finite Element Analysis of a New Furnace with Travelling Field Inductor for Induction Heating, Electromagnetic Stirring and Levitation of Molten Titanium Alloys

The study based on finite element (FE) models of the electromagnetic field and of the motion insi... more The study based on finite element (FE) models of the electromagnetic field and of the motion inside the volume of the levitated molten titanium alloy of a new induction furnace equipped with a travelling field inductor in this paper is focused on three important effects-induction heating, electromagnetic stirring and charge levitation. The main parameters of this study are the charge weight, the supply frequency and the relative position charge-inductor.

Research paper thumbnail of 3D magneto-thermal computations of electromagnetic induction phenomena

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, 2003

ABSTRACT This paper presents the results of a series of tests made in order to validate the magne... more ABSTRACT This paper presents the results of a series of tests made in order to validate the magneto-thermal module of the new FLUX3D v3.40. The tool was conceived to solve the coupled problems of electromagnetic and thermal phenomena. The solving method of the program considers a thermal-transient problem during a certain period of time and it solves, at each time step, the thermal and electromagnetic equations (in quasi-stationary magneto-harmonic formulation), alternatively. We have modelled the inductive longitudinal welding of steel pipes. The results of 3D simulations are compared with measurements on a laboratory device.

Research paper thumbnail of Finite Element Analysis of Cold Crucible Configurations for Efficient Induction Heating of a Large Range of Molten Glass Volumes with the Same Inductor and Electric Supply

Conference OPTIM-ACEMP 2021, 2021

Based on finite element models, this paper investigates different cold crucible configurations fo... more Based on finite element models, this paper investigates different cold crucible configurations for efficient induction heating of molten glass charges with volumes in a large range by using a unique inductor and electric supply. The performances of cold crucible induction furnaces with a new one-segment annular cold crucibles for molten glass charges with diameter independent on the charge volume or for charges that conserves the ratio charge diameter / height are compared with those of the usual furnace with multi-segment round tubes cold crucible. Keywords-cold crucible induction furnace; 3D finite element models, segmented annular cold crucibles, large range of molten glasses heated volumes I.

Research paper thumbnail of Finite Element Analysis of Cold Crucible Configurations for Efficient Induction Heating of a Large Range of Molten Glass Volumes with the Same Inductor and Electric Supply

2021 International Aegean Conference on Electrical Machines and Power Electronics (ACEMP) & 2021 International Conference on Optimization of Electrical and Electronic Equipment (OPTIM)

Research paper thumbnail of Influences on the electromagnetic torque and rotor force of different faults in squirrel-cage induction motors

International Journal of Applied Electromagnetics and Mechanics