Valentin Muller - Academia.edu (original) (raw)
Papers by Valentin Muller
An induction motor with unsymmetrical stator windings fed by three-phase unbalanced voltages is a... more An induction motor with unsymmetrical stator windings fed by three-phase unbalanced voltages is analyzed. It is a highly generalized case, where the method of the symmetrical components is applied. The symmetrical components of voltages and currents were determined, as well as the expressions of motor's positive, negative and zero sequence impedances. The obtained results allow the steady-state analysis of three-phase induction motors built with distinct types or values of stator windings asymmetry. KEYWORDS Unsymmetrical induction motor, symmetrical components. RESUMEN El trabajo analiza el motor de inducción trifásico con embobinados de estator no simétricos, alimentados por un sistema trifásico con voltajes desequilibrados. Se trata de un caso de un alto grado de generalización en que se aplica el método de los componentes simétricos. Se han determinado los componentes simétricos de las tensiones y corrientes así como las impedancias para secuencia positiva, negativa y cero. Los resultados obtenidos permiten el análisis, en régimen estacionario, de los motores de inducción trifásicos fabricados con distintos tipos o grados de asimetría en los embobinados del estator. PALABRAS CLAVE Motor de inducción no simétrico, componentes simétricos.
revue.elth.pub.ro
Rev. Roum. Sci. Techn. Électrotechn. et Énerg., 55, 3, p. 278288, Bucarest, 2010 ... COMPUTATI... more Rev. Roum. Sci. Techn. Électrotechn. et Énerg., 55, 3, p. 278288, Bucarest, 2010 ... COMPUTATION METHODS FOR SPACE HARMONIC EFFECTS ON SINGLE-PHASE INDUCTION MOTOR PERFORMANCE ... VALENTIN NĂVRĂPESCU1, MIRCEA POPESCU2, AUREL-IONUŢ CHIRILĂ1, IOAN-...
International Journal of Modern Manufacturing Technologies
The aim’s paper was to study some physico-mechanical properties for fashion tights and medicinal ... more The aim’s paper was to study some physico-mechanical properties for fashion tights and medicinal tights with compression degree 1 (ie 10-15 mm Hg), class 1, for the prevention of venous diseases of the legs. Tights made of PA (polyamide) and two-component yarns, polyamide, and elastane, with a fineness of 70 Den, were chosen for the study. For fashion tights, the yarn composition was 88% polyamide and 12% elastane, and for medicinal tights 85% polyamide and 15% elastane. The tights were made on circular knitting machines with small diameter, Merz, model CC4 II with a diameter of 4 ¾ inches, pitch 24 E, number of needles 360, for the average size, M (II) of the tights. Both types of women's tights were made in a jersey structure with weft yarns. The background yarns were 100% polyamide, and the weft yarns were elastomer yarns coated in two polyamide yarns to obtain a balanced yarn. Fashion tights are the common ones, and compressive tights are used to prevent incipient venous dis...
2022 International Conference and Exposition on Electrical And Power Engineering (EPE)
In this paper it is shown the variation of the rotor resistance and the dispersion reactance, mag... more In this paper it is shown the variation of the rotor resistance and the dispersion reactance, magnitudes reduced at the stator in coparison with the charge. 2R
New Technologies, Development and Application II
Current industrialization policy created a favourable context to the development of the automotiv... more Current industrialization policy created a favourable context to the development of the automotive industry, due to the discovery of the facilities that aluminum materials offer. Modification of the technology for production of aluminum wiring instead of copper wiring implies altering the quality control methods. The paper present the quality control methods used after the pulling, twisting and extrusion processes for the wiring. After their presentation, a series of optimization steps for the processes are presented.
New Technologies, Development and Application II
The newest trends in the automotive industry are focused on reducing material usage, building mor... more The newest trends in the automotive industry are focused on reducing material usage, building more efficient engines, using aluminum and composite materials.
In this paper are analyzed the operating characteristics at the rotorical parameters variation in... more In this paper are analyzed the operating characteristics at the rotorical parameters variation in comparison with the charge and in that conditions when rotorical parameters ' 2 ' 2 , X R are constant.
Revista Facultad De Ingenieria-universidad De Antioquia, 2006
This paper shows the performance of an induction generator with two triphases windings in stator,... more This paper shows the performance of an induction generator with two triphases windings in stator, and the choice of a suitable angle between the two windings in stator for getting a proper tension according to the value of the consumer connected at the generator terminals.
In this paper it is shown the variation of the rotor resistance and the dispersion reactance , ma... more In this paper it is shown the variation of the rotor resistance and the dispersion reactance , magnitudes reduced at the stator in coparison with the charge. ' 2 R ' 2 X
SCIENTIFIC RESEARCH AND EDUCATION IN THE AIR FORCE
This paper determines the value of capacitor connected in series with the auxiliary phase for a s... more This paper determines the value of capacitor connected in series with the auxiliary phase for a single-phase induction machine. Capacitance of the capacitor is determined by a certain gap between the main and auxiliary phase of the machine, having variable speed.
ANNALS OF THE ORADEA UNIVERSITY. Fascicle of Management and Technological Engineering., 2014
SCADA (Supervisory Control And Data Acquisition) systems represent applications trought which we ... more SCADA (Supervisory Control And Data Acquisition) systems represent applications trought which we can collect datas from a system in order to control and monitorise that system. So SCADA is in fact technology that gives the user the posibility to acquire data from one or more remote equipments and send a limited set of control instructions to those equipments. The purpose of this writing is a study of SCADA systems exemplified by a heating system.
Scientific and Technical Bulletin Series Electrotechnics Electronics Automatic Control and Computer Science, Mar 4, 2015
The paper is presenting the mathematical model of the transient regime of an induction machine. T... more The paper is presenting the mathematical model of the transient regime of an induction machine. The model is based on the equations of the induction machines from the theory of the two axes, resulting a non-linear system. The initial conditions are set according to the characteristics of the regime.
Revista Facultad De Ingenieria Universidad De Antioquia, 2006
How to cite Complete issue More information about this article Journal's homepage in redalyc.org ... more How to cite Complete issue More information about this article Journal's homepage in redalyc.org Scientific Information System Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Non-profit academic project, developed under the open access initiative
En este trabajo se presenta un método analítico para optimizar las barras Roebel, las cuales se u... more En este trabajo se presenta un método analítico para optimizar las barras Roebel, las cuales se utilizan para los arrollamientos de los motores eléctricos potentes de corriente alterna. La construcción es mediante conductores elementales. También se determinó el campo magnético radial
Anais da Academia Brasileira de Ciências, 2013
This paper establishes a mathematical model of induction machine connected to a frequency inverte... more This paper establishes a mathematical model of induction machine connected to a frequency inverter necessary to adjust the electric motor drive. The mathematical model based on the Park's theory allows the analysis of the whole spectrum (electric car – frequency inverter) to drive the electric trolley bus made on ASTRA Bus Arad (Romania). To remove higher order harmonics, the PWM waveform of supply voltage is used, set in the general case. Operating characteristics of electric motor drive are set to sub-nominal frequency (f < 50 Hz) and for different angles of the control switching elements in the construction of the inverter. Tensions in the stator of the equivalent machine are determined by three components: the fundamental component; the second component corresponding to the higher order harmonics, which rotate in direct connection; and the appropriate third component of higher order harmonics, which are rotated in reverse. The mathematical model developed will help to det...
An induction motor with unsymmetrical stator windings fed by three-phase unbalanced voltages is a... more An induction motor with unsymmetrical stator windings fed by three-phase unbalanced voltages is analyzed. It is a highly generalized case, where the method of the symmetrical components is applied. The symmetrical components of voltages and currents were determined, as well as the expressions of motor's positive, negative and zero sequence impedances. The obtained results allow the steady-state analysis of three-phase induction motors built with distinct types or values of stator windings asymmetry. KEYWORDS Unsymmetrical induction motor, symmetrical components. RESUMEN El trabajo analiza el motor de inducción trifásico con embobinados de estator no simétricos, alimentados por un sistema trifásico con voltajes desequilibrados. Se trata de un caso de un alto grado de generalización en que se aplica el método de los componentes simétricos. Se han determinado los componentes simétricos de las tensiones y corrientes así como las impedancias para secuencia positiva, negativa y cero. Los resultados obtenidos permiten el análisis, en régimen estacionario, de los motores de inducción trifásicos fabricados con distintos tipos o grados de asimetría en los embobinados del estator. PALABRAS CLAVE Motor de inducción no simétrico, componentes simétricos.
revue.elth.pub.ro
Rev. Roum. Sci. Techn. Électrotechn. et Énerg., 55, 3, p. 278288, Bucarest, 2010 ... COMPUTATI... more Rev. Roum. Sci. Techn. Électrotechn. et Énerg., 55, 3, p. 278288, Bucarest, 2010 ... COMPUTATION METHODS FOR SPACE HARMONIC EFFECTS ON SINGLE-PHASE INDUCTION MOTOR PERFORMANCE ... VALENTIN NĂVRĂPESCU1, MIRCEA POPESCU2, AUREL-IONUŢ CHIRILĂ1, IOAN-...
International Journal of Modern Manufacturing Technologies
The aim’s paper was to study some physico-mechanical properties for fashion tights and medicinal ... more The aim’s paper was to study some physico-mechanical properties for fashion tights and medicinal tights with compression degree 1 (ie 10-15 mm Hg), class 1, for the prevention of venous diseases of the legs. Tights made of PA (polyamide) and two-component yarns, polyamide, and elastane, with a fineness of 70 Den, were chosen for the study. For fashion tights, the yarn composition was 88% polyamide and 12% elastane, and for medicinal tights 85% polyamide and 15% elastane. The tights were made on circular knitting machines with small diameter, Merz, model CC4 II with a diameter of 4 ¾ inches, pitch 24 E, number of needles 360, for the average size, M (II) of the tights. Both types of women's tights were made in a jersey structure with weft yarns. The background yarns were 100% polyamide, and the weft yarns were elastomer yarns coated in two polyamide yarns to obtain a balanced yarn. Fashion tights are the common ones, and compressive tights are used to prevent incipient venous dis...
2022 International Conference and Exposition on Electrical And Power Engineering (EPE)
In this paper it is shown the variation of the rotor resistance and the dispersion reactance, mag... more In this paper it is shown the variation of the rotor resistance and the dispersion reactance, magnitudes reduced at the stator in coparison with the charge. 2R
New Technologies, Development and Application II
Current industrialization policy created a favourable context to the development of the automotiv... more Current industrialization policy created a favourable context to the development of the automotive industry, due to the discovery of the facilities that aluminum materials offer. Modification of the technology for production of aluminum wiring instead of copper wiring implies altering the quality control methods. The paper present the quality control methods used after the pulling, twisting and extrusion processes for the wiring. After their presentation, a series of optimization steps for the processes are presented.
New Technologies, Development and Application II
The newest trends in the automotive industry are focused on reducing material usage, building mor... more The newest trends in the automotive industry are focused on reducing material usage, building more efficient engines, using aluminum and composite materials.
In this paper are analyzed the operating characteristics at the rotorical parameters variation in... more In this paper are analyzed the operating characteristics at the rotorical parameters variation in comparison with the charge and in that conditions when rotorical parameters ' 2 ' 2 , X R are constant.
Revista Facultad De Ingenieria-universidad De Antioquia, 2006
This paper shows the performance of an induction generator with two triphases windings in stator,... more This paper shows the performance of an induction generator with two triphases windings in stator, and the choice of a suitable angle between the two windings in stator for getting a proper tension according to the value of the consumer connected at the generator terminals.
In this paper it is shown the variation of the rotor resistance and the dispersion reactance , ma... more In this paper it is shown the variation of the rotor resistance and the dispersion reactance , magnitudes reduced at the stator in coparison with the charge. ' 2 R ' 2 X
SCIENTIFIC RESEARCH AND EDUCATION IN THE AIR FORCE
This paper determines the value of capacitor connected in series with the auxiliary phase for a s... more This paper determines the value of capacitor connected in series with the auxiliary phase for a single-phase induction machine. Capacitance of the capacitor is determined by a certain gap between the main and auxiliary phase of the machine, having variable speed.
ANNALS OF THE ORADEA UNIVERSITY. Fascicle of Management and Technological Engineering., 2014
SCADA (Supervisory Control And Data Acquisition) systems represent applications trought which we ... more SCADA (Supervisory Control And Data Acquisition) systems represent applications trought which we can collect datas from a system in order to control and monitorise that system. So SCADA is in fact technology that gives the user the posibility to acquire data from one or more remote equipments and send a limited set of control instructions to those equipments. The purpose of this writing is a study of SCADA systems exemplified by a heating system.
Scientific and Technical Bulletin Series Electrotechnics Electronics Automatic Control and Computer Science, Mar 4, 2015
The paper is presenting the mathematical model of the transient regime of an induction machine. T... more The paper is presenting the mathematical model of the transient regime of an induction machine. The model is based on the equations of the induction machines from the theory of the two axes, resulting a non-linear system. The initial conditions are set according to the characteristics of the regime.
Revista Facultad De Ingenieria Universidad De Antioquia, 2006
How to cite Complete issue More information about this article Journal's homepage in redalyc.org ... more How to cite Complete issue More information about this article Journal's homepage in redalyc.org Scientific Information System Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Non-profit academic project, developed under the open access initiative
En este trabajo se presenta un método analítico para optimizar las barras Roebel, las cuales se u... more En este trabajo se presenta un método analítico para optimizar las barras Roebel, las cuales se utilizan para los arrollamientos de los motores eléctricos potentes de corriente alterna. La construcción es mediante conductores elementales. También se determinó el campo magnético radial
Anais da Academia Brasileira de Ciências, 2013
This paper establishes a mathematical model of induction machine connected to a frequency inverte... more This paper establishes a mathematical model of induction machine connected to a frequency inverter necessary to adjust the electric motor drive. The mathematical model based on the Park's theory allows the analysis of the whole spectrum (electric car – frequency inverter) to drive the electric trolley bus made on ASTRA Bus Arad (Romania). To remove higher order harmonics, the PWM waveform of supply voltage is used, set in the general case. Operating characteristics of electric motor drive are set to sub-nominal frequency (f < 50 Hz) and for different angles of the control switching elements in the construction of the inverter. Tensions in the stator of the equivalent machine are determined by three components: the fundamental component; the second component corresponding to the higher order harmonics, which rotate in direct connection; and the appropriate third component of higher order harmonics, which are rotated in reverse. The mathematical model developed will help to det...