EPE Association: EPE 1985 - 17 - Lecture Session 3.03: INDUCTION MOTOR DRIVES: STEADY STATE ANALYSIS

EPE 1985 - 17 - Lecture Session 3.03: INDUCTION MOTOR DRIVES: STEADY STATE ANALYSIS
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1985 - Conference > EPE 1985 - 17 - Lecture Session 3.03: INDUCTION MOTOR DRIVES: STEADY STATE ANALYSIS

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   A SELF-CONTROLLED INDUCTION MOTOR DRIVE
By A. L. Aguiar; H. Foch; J. P. Arches [View]
[Download]

Abstract: This paper presents the conception and implementation of a self-controlled induction motor drive. The motor is fed by a voltage source inverter made up with six self-controlled switches with spontaneous turn-on and turn-off, and the drive inherently realizes an internal V/f control law, without the need of any additional external logic circuits. By using Bipolar-MOS pairs as the controllable power elements of the switches, it is demonstrated that the inverter provides highly simplified auxiliary circuits with great reliability. Experimental results concerning a 3 kW induction motor drive are presented and discussed.

   ON THE STEADY-STATE PERFORMANCE OF A TRANSISTORIZED PWM INVERTER INDUCTION MOTOR DRIVE SYSTEM FOR HIGH SPEED
By E. Ch. Andresen; A. Schindler [View]
[Download]

Abstract: A specially designed high speed drive system consisting of a 3-phase a.c. squirrel cage induction motor and a transistorized PWM frequency inverter is presented. The motor power output is 10 kW at rated pole flux, 400 Hz stator frequency and 12000 r.p.m. The inverter is rated for 15 kVA, 400 V and 37 A. The pulse width modulation works in the two-step mode with constant frequency adjustable from 1,25 to 20kHz in 16 steps. Harmonic analysis reveals that the amplitudes of the motor phase voltages get minimum when timing the pulse periods of the three inverter phases without phase shift. Though generating single phase MMF waves in addition to three phase MMF waves this mode causes the smallest harmonic effects in the machine. Computer simulation shows that mechanical resonance oscillations (393 Hz) are excited when operating the inverter with low pulse frequencies and that oscillations disappear at high frequencies. The measured additional losses of the motor (10 to 18 % of the rated power output) are approximately halved through changing the modulation frequency from 1,25 to 10 kHz. A study of the calculated loss components shows that the additional losses can be decreased only little by increasing the leakage inductances and by applying laminations with very low magnetiziation losses.

   AN ECONOMIC VERY HIGH POWER PWM INVERTER FOR INDUCTION MOTOR DRIVES
By J. Holtz; S. Stadtfeld; P. Lammert [View]
[Download]

Abstract: A novel PWM inverter operates at high dc link voltage. The output voltage can assume three different levels (three-state inverter). The principle of temporary series connection of different power semiconductors avoids dynamic overvoltages that are usually encountered with series connected power switches. In the thyristorized version which is presented here, the commutation is performed with a single current pulse that is supplied by a comparatively small commutation capacitor. There are no high turn-on currents in the main thyristors. The high utilization of the active and passive components of the circuit permits the application at a high power level of several megawatts. The three different levels of the output voltage allow the operation at a low switching frequency with reduced harmonic currents. An optimal PWM control algorithm is implemented in a 16 bit microprocessor. Experimental results obtained with a 650 kVA induction motor drive system are presented.

   LE FACTEUR DE DEPLACEMENT D'UN COURANT DU MOTEUR ASYNCHRONE PROFONDEMENT ENCOCHE ALIMENTE PAR L'ONDULEUR THYRISTORIQUE VOLTMETRIQUE
By K. Jagiela [View]
[Download]

Abstract: Dans cet article, on a présenté !'analyse de la dynamique du moteur asynchrone à encoche profonde. On a pris en considération le phénomène de déplacement du courant dans les barres de cage du rotor. On a fait ces calculs, en posant en principe que le moteur est alimenté par l'onduleur thyristorique voltmetrique. Ces résultats reçus des calculs numériques ont permis de présenter la relation de coefficient de déplacement du courant kR en fonction de fréquence relative f pour de différents parametres du vecteur de commande v(t) = [ U,Mz ] T.

   EFFICIENCY EVALUATION OF INDUCTION MOTOR DRIVES IN INDUSTRIAL APPLICATIONS
By A. Consoli; A. Raciti [View]
[Download]

Abstract: The paper deals with an actual induction motor used in high energy consumption applications. Different inverter configurations driving the same machine are considered, and theoretical tools for comparison of such configurations are established, essentially based on efficiency evaluations. Two different methods, an equivalent circuit analysis and a direct modeling technique are proposed in order to deduce the effective inverter voltage or current outputs feeding the motor. The motor and the overall system efficiencies are then evaluated, taking into account all motor and inverter losses. Experimental tests are also presented, showing validation of the cormputer predicted results.

   PHASE NUMBER OF INVERTER-FED INDUCTION MOTORS: EFFECTS ON THE DC LINK HARMONICS CONTENTS
By P. Ferraris; M. Lazzari; F. Profumo [View]
[Download]

Abstract: The electrical drives constituted by an induction motor fed throuqh a voltaqe source inverter may present problems related to current harmonics introduced on the D.C. link; that may pose environmental problems, particulary in traction applications, in qeneral filterinq problems which sometimes may be particularly onerous, or problems due to torque pulsations. Those aspects may result even more important for the case of motor supply technique of the type six-steps or similar, which may constitute a good solution for a wide field of applications. A technique which allows of increasing the harmonics frequency and affecting the noise problems, without alterating the inverter's commutation frequency, is the one based on the choice of a motor phases number greater than three. In such conditions the phases number may be considered a new free parameter which has to be optimized; a general discussion on such argument has been performed by the authors mainly with regards to the basic problems related to the different phase connection techniques, which are possible when the phases number increases. The new different solutions, for a wide range of the phases number M and the choice of their connecting methodologies, are analysed in the paper under the point of view of the effects on the D.C. link harmonic contents, and on the torque pulsations amount.

EPE 1985 - 17 - Lecture Session 3.03: INDUCTION MOTOR DRIVES: STEADY STATE ANALYSIS
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1985 - Conference > EPE 1985 - 17 - Lecture Session 3.03: INDUCTION MOTOR DRIVES: STEADY STATE ANALYSIS
	[return to parent folder]

	A SELF-CONTROLLED INDUCTION MOTOR DRIVE By A. L. Aguiar; H. Foch; J. P. Arches	[View] [Download]
Abstract: This paper presents the conception and implementation of a self-controlled induction motor drive. The motor is fed by a voltage source inverter made up with six self-controlled switches with spontaneous turn-on and turn-off, and the drive inherently realizes an internal V/f control law, without the need of any additional external logic circuits. By using Bipolar-MOS pairs as the controllable power elements of the switches, it is demonstrated that the inverter provides highly simplified auxiliary circuits with great reliability. Experimental results concerning a 3 kW induction motor drive are presented and discussed.

	ON THE STEADY-STATE PERFORMANCE OF A TRANSISTORIZED PWM INVERTER INDUCTION MOTOR DRIVE SYSTEM FOR HIGH SPEED By E. Ch. Andresen; A. Schindler	[View] [Download]
Abstract: A specially designed high speed drive system consisting of a 3-phase a.c. squirrel cage induction motor and a transistorized PWM frequency inverter is presented. The motor power output is 10 kW at rated pole flux, 400 Hz stator frequency and 12000 r.p.m. The inverter is rated for 15 kVA, 400 V and 37 A. The pulse width modulation works in the two-step mode with constant frequency adjustable from 1,25 to 20kHz in 16 steps. Harmonic analysis reveals that the amplitudes of the motor phase voltages get minimum when timing the pulse periods of the three inverter phases without phase shift. Though generating single phase MMF waves in addition to three phase MMF waves this mode causes the smallest harmonic effects in the machine. Computer simulation shows that mechanical resonance oscillations (393 Hz) are excited when operating the inverter with low pulse frequencies and that oscillations disappear at high frequencies. The measured additional losses of the motor (10 to 18 % of the rated power output) are approximately halved through changing the modulation frequency from 1,25 to 10 kHz. A study of the calculated loss components shows that the additional losses can be decreased only little by increasing the leakage inductances and by applying laminations with very low magnetiziation losses.

	AN ECONOMIC VERY HIGH POWER PWM INVERTER FOR INDUCTION MOTOR DRIVES By J. Holtz; S. Stadtfeld; P. Lammert	[View] [Download]
Abstract: A novel PWM inverter operates at high dc link voltage. The output voltage can assume three different levels (three-state inverter). The principle of temporary series connection of different power semiconductors avoids dynamic overvoltages that are usually encountered with series connected power switches. In the thyristorized version which is presented here, the commutation is performed with a single current pulse that is supplied by a comparatively small commutation capacitor. There are no high turn-on currents in the main thyristors. The high utilization of the active and passive components of the circuit permits the application at a high power level of several megawatts. The three different levels of the output voltage allow the operation at a low switching frequency with reduced harmonic currents. An optimal PWM control algorithm is implemented in a 16 bit microprocessor. Experimental results obtained with a 650 kVA induction motor drive system are presented.

	LE FACTEUR DE DEPLACEMENT D'UN COURANT DU MOTEUR ASYNCHRONE PROFONDEMENT ENCOCHE ALIMENTE PAR L'ONDULEUR THYRISTORIQUE VOLTMETRIQUE By K. Jagiela	[View] [Download]
Abstract: Dans cet article, on a présenté !'analyse de la dynamique du moteur asynchrone à encoche profonde. On a pris en considération le phénomène de déplacement du courant dans les barres de cage du rotor. On a fait ces calculs, en posant en principe que le moteur est alimenté par l'onduleur thyristorique voltmetrique. Ces résultats reçus des calculs numériques ont permis de présenter la relation de coefficient de déplacement du courant kR en fonction de fréquence relative f pour de différents parametres du vecteur de commande v(t) = [ U,Mz ] T.

	EFFICIENCY EVALUATION OF INDUCTION MOTOR DRIVES IN INDUSTRIAL APPLICATIONS By A. Consoli; A. Raciti	[View] [Download]
Abstract: The paper deals with an actual induction motor used in high energy consumption applications. Different inverter configurations driving the same machine are considered, and theoretical tools for comparison of such configurations are established, essentially based on efficiency evaluations. Two different methods, an equivalent circuit analysis and a direct modeling technique are proposed in order to deduce the effective inverter voltage or current outputs feeding the motor. The motor and the overall system efficiencies are then evaluated, taking into account all motor and inverter losses. Experimental tests are also presented, showing validation of the cormputer predicted results.

	PHASE NUMBER OF INVERTER-FED INDUCTION MOTORS: EFFECTS ON THE DC LINK HARMONICS CONTENTS By P. Ferraris; M. Lazzari; F. Profumo	[View] [Download]
Abstract: The electrical drives constituted by an induction motor fed throuqh a voltaqe source inverter may present problems related to current harmonics introduced on the D.C. link; that may pose environmental problems, particulary in traction applications, in qeneral filterinq problems which sometimes may be particularly onerous, or problems due to torque pulsations. Those aspects may result even more important for the case of motor supply technique of the type six-steps or similar, which may constitute a good solution for a wide field of applications. A technique which allows of increasing the harmonics frequency and affecting the noise problems, without alterating the inverter's commutation frequency, is the one based on the choice of a motor phases number greater than three. In such conditions the phases number may be considered a new free parameter which has to be optimized; a general discussion on such argument has been performed by the authors mainly with regards to the basic problems related to the different phase connection techniques, which are possible when the phases number increases. The new different solutions, for a wide range of the phases number M and the choice of their connecting methodologies, are analysed in the paper under the point of view of the effects on the D.C. link harmonic contents, and on the torque pulsations amount.