EPE Association: EPE 1985 - 19 - Lecture Session 3.05: CURRENT SOURCE INVERTER-FED INDUCTION MOTOR DRIVES

EPE 1985 - 19 - Lecture Session 3.05: CURRENT SOURCE INVERTER-FED INDUCTION MOTOR DRIVES
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1985 - Conference > EPE 1985 - 19 - Lecture Session 3.05: CURRENT SOURCE INVERTER-FED INDUCTION MOTOR DRIVES

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   HIGH FREQUENCY CHARACTERISTICS OF NEW CURRENT SOURCE GTO INVERTER-FED INDUCTION MOTOR DRIVE
By H. Kubota; K. Matsuse [View]
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Abstract: A current source inverter is widely used to drive an AC motor, because the inverter has many advantages, such as full four quadrant regenerative capability, and short circuit proof capability. However, a conventional autosequentially commutated current source inverter (ASCI) needs a long commutation delay time. Therefore, the upper limit of an operating frequency is relatively low. And also, existence of many commutation capacitors makes the inverter larger and less efficient. For this reason, we (Matsuse, Hashimoto, Kubota, Ree, 1983, 1985) proposed a new current source inverter, which uses gate turn-off thyristors (GTO) in the main circuit and does not need essentially commutation delay. The reactive power in a load is stored into a capacitor temporally, and then it is discharged into the DC circuit. This method of treating the reactive power is applied to the conventional ASCI to make the voltage spike lower in a commutation (Cho and Park, 1981; Palaniappan, 1982). In the case of the proposed inverter, commutation characteristics are variable according to the discharging period, that is, the capacitor voltage. The proposed inverter is able to drive an induction motor at a higher frequency than conventional current source inverters. Therefore, we must investigate the high frequency characteristics of the proposed current source inverter-fed induction motor drive. In this paper, the characteristics of the inverter, especially commutation characteristics, are described on the basis of the analysis and experimental results.

   COMPARATIVE STEADY-STATE ANALYSIS OF 3-PHASE CURRENT SOURCE CONVERTER FED INDUCTION MOTORS
By N. S. Gehlot; J. Gomes de Matos [View]
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Abstract: This paper presents a comparative steady-state analysis of 3-phase Current Source Converter fed induction motors. The converter-motor system is modeled by three different models of increasing complexity, taking into account, the commutation process, the machine saturation, the variation of the motor counter EMF during commutation, the phase-shift of the fundamental line current with respect to the ideal current waveform due to finite coommutation time, the stator resistance, and the complete machine representation. Iterative computations of the trancendental and the closed-form equations are realized to obtain analysis, waveforms, characteristics, and system design criteria. The computed results of the three models are compared with the laboratory test results on two machines. The computed results match very closely with the laboratory test results.

   A MlCROPROCESSOR CONTROL FOR CSI-CONVERTER DRIVES WlTH INDUCTION MOTORS
By B. Kampschulte [View]
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Abstract: The paper presents a microprocessor control for a CSI induction motor drive. One uP handles all tasks including the two firing units of the converter and the machine control. The induction motor is controlled by a field oriented procedure without speed feedback. A machine model computes the reference values of current and slip frequency. The stator frequency is adjusted by a power control loop which corrects parameter deviations as well.

   ATTENUATION OF THE EFFECT OF THE TORQUE PULSATION IN AN ASYNCHRONOUS MACHINE FED BY A CURRENT SOURCE INVERTER
By C. Yechouroun [View]
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Abstract: The first part of this paper deals with a PWM commutation control for a current source inverter feeding an asynchronous machine. The required purpose is to obtain the instantaneous average value of the phase current close to a sine curve. Secondly, we will introduce a possibility of suppressing the pulsation regarding the torque by modulating the current source; the control value of the current will be calculated by means of the reference torque (given by the speed controller) and the magnetic flux. The calculation of this flux is resolved from an algorithm based on the asynchronous machine model.

   INDUCTION MOTOR-CURRENT SOURCE INVERTER SYSTEMS WITH PHASE NUMBER GREATER THAN 3
By J. Dente; F. Labrique [View]
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Abstract: This paper describes economical current source inverters suited for feeding induction motors with more than three phases. The proposed inverters have phase numbers which are multiples of two or three and they use respectively the same number of commutating capacitors as the classical single phase or three phase inverter with series diodes. The influence of the number of phases on the reduction of the commutating capacitor size and of the peak commutating voltages is investigated. Experiments confirm the theoretical predictions.

EPE 1985 - 19 - Lecture Session 3.05: CURRENT SOURCE INVERTER-FED INDUCTION MOTOR DRIVES
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1985 - Conference > EPE 1985 - 19 - Lecture Session 3.05: CURRENT SOURCE INVERTER-FED INDUCTION MOTOR DRIVES
	[return to parent folder]

	HIGH FREQUENCY CHARACTERISTICS OF NEW CURRENT SOURCE GTO INVERTER-FED INDUCTION MOTOR DRIVE By H. Kubota; K. Matsuse	[View] [Download]
Abstract: A current source inverter is widely used to drive an AC motor, because the inverter has many advantages, such as full four quadrant regenerative capability, and short circuit proof capability. However, a conventional autosequentially commutated current source inverter (ASCI) needs a long commutation delay time. Therefore, the upper limit of an operating frequency is relatively low. And also, existence of many commutation capacitors makes the inverter larger and less efficient. For this reason, we (Matsuse, Hashimoto, Kubota, Ree, 1983, 1985) proposed a new current source inverter, which uses gate turn-off thyristors (GTO) in the main circuit and does not need essentially commutation delay. The reactive power in a load is stored into a capacitor temporally, and then it is discharged into the DC circuit. This method of treating the reactive power is applied to the conventional ASCI to make the voltage spike lower in a commutation (Cho and Park, 1981; Palaniappan, 1982). In the case of the proposed inverter, commutation characteristics are variable according to the discharging period, that is, the capacitor voltage. The proposed inverter is able to drive an induction motor at a higher frequency than conventional current source inverters. Therefore, we must investigate the high frequency characteristics of the proposed current source inverter-fed induction motor drive. In this paper, the characteristics of the inverter, especially commutation characteristics, are described on the basis of the analysis and experimental results.

	COMPARATIVE STEADY-STATE ANALYSIS OF 3-PHASE CURRENT SOURCE CONVERTER FED INDUCTION MOTORS By N. S. Gehlot; J. Gomes de Matos	[View] [Download]
Abstract: This paper presents a comparative steady-state analysis of 3-phase Current Source Converter fed induction motors. The converter-motor system is modeled by three different models of increasing complexity, taking into account, the commutation process, the machine saturation, the variation of the motor counter EMF during commutation, the phase-shift of the fundamental line current with respect to the ideal current waveform due to finite coommutation time, the stator resistance, and the complete machine representation. Iterative computations of the trancendental and the closed-form equations are realized to obtain analysis, waveforms, characteristics, and system design criteria. The computed results of the three models are compared with the laboratory test results on two machines. The computed results match very closely with the laboratory test results.

	A MlCROPROCESSOR CONTROL FOR CSI-CONVERTER DRIVES WlTH INDUCTION MOTORS By B. Kampschulte	[View] [Download]
Abstract: The paper presents a microprocessor control for a CSI induction motor drive. One uP handles all tasks including the two firing units of the converter and the machine control. The induction motor is controlled by a field oriented procedure without speed feedback. A machine model computes the reference values of current and slip frequency. The stator frequency is adjusted by a power control loop which corrects parameter deviations as well.

	ATTENUATION OF THE EFFECT OF THE TORQUE PULSATION IN AN ASYNCHRONOUS MACHINE FED BY A CURRENT SOURCE INVERTER By C. Yechouroun	[View] [Download]
Abstract: The first part of this paper deals with a PWM commutation control for a current source inverter feeding an asynchronous machine. The required purpose is to obtain the instantaneous average value of the phase current close to a sine curve. Secondly, we will introduce a possibility of suppressing the pulsation regarding the torque by modulating the current source; the control value of the current will be calculated by means of the reference torque (given by the speed controller) and the magnetic flux. The calculation of this flux is resolved from an algorithm based on the asynchronous machine model.

	INDUCTION MOTOR-CURRENT SOURCE INVERTER SYSTEMS WITH PHASE NUMBER GREATER THAN 3 By J. Dente; F. Labrique	[View] [Download]
Abstract: This paper describes economical current source inverters suited for feeding induction motors with more than three phases. The proposed inverters have phase numbers which are multiples of two or three and they use respectively the same number of commutating capacitors as the classical single phase or three phase inverter with series diodes. The influence of the number of phases on the reduction of the commutating capacitor size and of the peak commutating voltages is investigated. Experiments confirm the theoretical predictions.