EPE Association: EPE 1993 - 57 - Dialogue Session DS4.6: DRIVES: SIMULATION CONTROL

EPE 1993 - 57 - Dialogue Session DS4.6: DRIVES: SIMULATION CONTROL
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1993 - Conference > EPE 1993 - 57 - Dialogue Session DS4.6: DRIVES: SIMULATION CONTROL

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   EXPERIENCE OF THE USE OF ASIC METHODS IN A MOTOR CONTROL APPLICATION
By D. J. Kinniment; E. Kappos; P. P. Acarnley [View]
[Download]

Abstract: This paper describes experience in the use of ASIC design in the control of the speed and torque of a Brushless DC motor. Considerable improvements in both system costs and performance can be achieved when compared with microprocessor based or discrete component designs, but the design methodology necessary to achieve a correct and reliable system leads to a long design cycle without prototype hardware. As part of this extended design process many of the activities normally carried out after the completion of a prototype (for example system tests) must be completed before device fabrication. Whilst this can be seen as a disadvantage by potential users, accurate system models in software form may be able to provide more information on the functioning of the systems in more extreme conditions, than would be possible with the actual hardware.

   High Performance Ultra-Low Speed Control of Inverter-Fed Linear Induction Motor Using Vector Control Scheme
By Y. Ogino; Y. Murakami; K.Ohishi; M. Nakaoka [View]
[Download]

Abstract: This paper presents the ultra low speed control scheme for inverter-fed LIM (Linear Inductlon Motor). From a practical point of view, its control method is based on the vector control strategy using the current controlled VVVF inverter. This system has the quick speed response and the smooth thrust characteristics in the ultra low speed range. This paper shows the experimental results of the tested LIM control system, and discusses its desired operating characteristics.

   RECURSIVE CONTROL OF ROBOT MANIPULATOR WITH ELASTICITY
By H. Yan; T. Murakami; K. Yuki; K. Ohnishi [View]
[Download]

Abstract: This paper presents an advanced method for suppressing torsional vibration of a flexible joint which connects a motor shaft and a driven arm. In the proposed method, at first, the position controller is designed on the basis of a model of rigid arm by recursive control law. After that, a compensation element is added to increase the stability of the total system, where only motor velocity is used for the purpose. The proposed method realizes a robust control and because of its model-free structure it is easy to implement the proposed algorithm. Experimental results are also presented to show its effectiveness.

   AN EFFICIENT TORQUE SPEED CHARACTERISTIC CALCULATION METHOD FOR BRUSHLESS C.A.D. USING OPTIMIZATION TECHNIQUES
By S. Clenet; S. Astier; J. Cros; Y. Lefèvre; M. Lajoie-Mazenc [View]
[Download]

Abstract: Nowadays, powerful tools enable to simulate the werk of inverter fed machine systems. But, they generally require long calculation times and large memory capacities and many parameters. So, they are not well adapted for an iterative design. In this paper, we present an efficient model, based on optimization techniques, for current fed synchronous machines fed by means of current controlled voltage inverter which leads to very short calculation times to determine torque speed characteristic of such an actuator. The limits of the valitidy of this model are discussed and simulated results are compared to experimental ones for validation.

   A TORQUE CONTROL STRATEGY FOR MOTOR STARTERS
By Hung T. Nguyen; Frank Bartolo [View]
[Download]

Abstract: In heavy industries such as coal mining or quarry products, solid-state motor starters for induction motors have been used extensively to bring conveyor systems to full speed because of their softstart capability. A major problem for industrial motor starters using the standard voltage ramping technique is that they usually experience inconsistent overall motor run-up time and instability near full speed. Current industrial solutions for this problem require the use of current feedback or tacho feedback. In this paper, we show that the standard voltage ramp currently used in industrial motor starters does not correlate to the run-up time, nor guarantees substantial eduction of torque and current surges. Digital implementation of a voltage ramping power starter indeed confirms the validity of these results. A torque-control strategy is then proposed for motor starter which would provide substantial reduction of torque and current surges, at the same time would guarantee the required run-up time of the induction motor without the use of a tacho-generator. Experimental results show that an effective torque-controlled power starter can be implemented successfully.

   A NOVEL VOLTS / HERTZ CONTROL METHOD FOR AN INDUCTION MOTOR TO IMPROVE THE TORQUE CHARACTERISTICS IN THE LOW SPEED RANGE
By T. Kataoka; Y. Sato; A. Bendiabdellah [View]
[Download]

Abstract: The volts/hertz controlled induction motors are widely used in industries because of their simple control system configurations. In such motors the influence of stator resistance drop becomes large in the low speed range, and compensation of this voltage drop is necessary to prevent a decrease in the developed torque. In this paper a novel volts/hertz control method to improve the torque characteristics in the low speed range is presented. This method is based on on-line calculation of rotor flux information from the reactive power of the motor. The calculated result is controlled so as to coincide with its reference signal. As a result, a linear torque to slip frequency characteristic is obtained. Since no knowledge of stator resistance is required, the torque characteristics become insensitive to stator resistance variations due to temperature variations. Experimental results are included to confirm the effectiveness of the proposed control method.

   INTELLIGENT DRIVES IN SYSTEMS WITH DECENTRALIZED INTELLIGENCE
By R. Schönfeld; M. Franke; H. Hasan; F. Müller [View]
[Download]

Abstract: An opportunity to substitute mechanical gear systems in packaging machines by a system of intelligent single drives in order to get more flexibility will be presented in this paper. The single drives are coupled via a serial bus. Starting from a definition of basic functions of an intelligent drive, a practical realization will be presented. This section includes a short description of the used control structure, a possibility of reference generation and the used thermal model for monitoring the drive temperature too. The features of the bus system used for the coupling of the drives are discussed in a following section. Tools for the description of such a drive system are necessary for its design, simulation and starting up and can be based e.g. on a function chart. Last but not least a pouch-, form-, fill- and seal-machine equipped with a system of intelligent single drives is presented.

   HIGH EFFICIENCY, LONG LIFE ACTUATOR FOR PV WATER PUMPING APPLICATIONS
By R. Liebenberg; J. H. R. Enslin; F. S. van der Merwe [View]
[Download]

Abstract: In practise, a typical diaphragm configuration, photovoltaic (PV) water pumping system consists of a DC permanent magnet motor driving a diaphragm pump via a cam. The typical efficiency is low and its life span short compared to that of the average solar cell. A better solution to the problems of low cost PV water pumping systems with low flow rates is introduced. The use of a linear DC motor or actuator as drive is suggested. A higher efficiency and life expectancy can be achieved for it has less friction and no cam losses. The aims of the project were to establish the required thrust force and stroke length, evaluate possible electromagnetic configurations by making use of a Finite Element Analysis (FEA) package and finally to evaluate different electromechanical options. The results obtained for these criteria will be discussed concluding with a choice of the best topology.

   AN IDEAL PWM-VSI INVERTER WITH FEEDFORWARD AND FEEDBACK COMPENSATION
By John K. Pedersen; Frede Blaabjerg; Johnny W. Jensen; Paul Thogersen [View]
[Download]

Abstract: This paper presents different compensation techniques based on feedforward and feedback techniques for obtaining an ideal PWM-VSI inverter to AC-machines. Unlinearities like blanking-time, voltage drop across the power devices and DC-link voltage ripple cause torque and speed fluctuations in the AC-machine. Different techniques are proposed and tested for eliminating these unlinearities. The blanking-time compensation is done by both a phase current feedforward and a voltage vector feedback. The voltage drop compensation is realized with a current feedforward and finally the DC-link voltage ripple is compensated by a feedforward of the measured DC-link voltage. A comparison and the influence of the different compensation technique are done on a 16-bit microcontroller based PWM-VSI inverter. Test results show a significant improved performance of the AC-machine at no load and at low speed when the compensation techniques are used.

   VECTOR CONTROLLED DRIVES IN A STEEL PROCESSING APPLICATION
By R. Jones; W. Wymeersch; P. Lataire [View]
[Download]

Abstract: A Belgian sheet steel manufacturer has specified a new range of a.c. variable speed drives as part of the upgrading of a discontinuous tandem cold mill (TCM) to a continuous process coupled with the preceding pickle line. The conversion of the TCM required the inclusion of a continuous exit section consisting mainly of d.c. driven tension reels and flying shear. Four quadrant, line regenerative, a.c. vector controlled drives have been selected to meet the performance requirement of the associated pinch, deflector and shape measuring rolls, necessary during an automatic reel changeover at 250 metres per minute and during the rapid controlled stopping duty. The small size of the induction motors, for the required overload torque rating, and the dynamic performance possibilities offered by these latest 4 quadrant drives were factors influencing the choice for this exacting application. The paper will focus on the performance capabilities of induction motors in developing overload torques of many times their full load rating for rapid speed changes. Comparisons will be made between the calculated results from equivalent circuit models of the induction motors and measurements taken from production equipments. A brief description of the other features incorporated into this range of a.c. drives gives an insight into the potential that such products offer for a wide range of high performance applications.

EPE 1993 - 57 - Dialogue Session DS4.6: DRIVES: SIMULATION CONTROL
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1993 - Conference > EPE 1993 - 57 - Dialogue Session DS4.6: DRIVES: SIMULATION CONTROL
	[return to parent folder]

	EXPERIENCE OF THE USE OF ASIC METHODS IN A MOTOR CONTROL APPLICATION By D. J. Kinniment; E. Kappos; P. P. Acarnley	[View] [Download]
Abstract: This paper describes experience in the use of ASIC design in the control of the speed and torque of a Brushless DC motor. Considerable improvements in both system costs and performance can be achieved when compared with microprocessor based or discrete component designs, but the design methodology necessary to achieve a correct and reliable system leads to a long design cycle without prototype hardware. As part of this extended design process many of the activities normally carried out after the completion of a prototype (for example system tests) must be completed before device fabrication. Whilst this can be seen as a disadvantage by potential users, accurate system models in software form may be able to provide more information on the functioning of the systems in more extreme conditions, than would be possible with the actual hardware.

	High Performance Ultra-Low Speed Control of Inverter-Fed Linear Induction Motor Using Vector Control Scheme By Y. Ogino; Y. Murakami; K.Ohishi; M. Nakaoka	[View] [Download]
Abstract: This paper presents the ultra low speed control scheme for inverter-fed LIM (Linear Inductlon Motor). From a practical point of view, its control method is based on the vector control strategy using the current controlled VVVF inverter. This system has the quick speed response and the smooth thrust characteristics in the ultra low speed range. This paper shows the experimental results of the tested LIM control system, and discusses its desired operating characteristics.

	RECURSIVE CONTROL OF ROBOT MANIPULATOR WITH ELASTICITY By H. Yan; T. Murakami; K. Yuki; K. Ohnishi	[View] [Download]
Abstract: This paper presents an advanced method for suppressing torsional vibration of a flexible joint which connects a motor shaft and a driven arm. In the proposed method, at first, the position controller is designed on the basis of a model of rigid arm by recursive control law. After that, a compensation element is added to increase the stability of the total system, where only motor velocity is used for the purpose. The proposed method realizes a robust control and because of its model-free structure it is easy to implement the proposed algorithm. Experimental results are also presented to show its effectiveness.

	AN EFFICIENT TORQUE SPEED CHARACTERISTIC CALCULATION METHOD FOR BRUSHLESS C.A.D. USING OPTIMIZATION TECHNIQUES By S. Clenet; S. Astier; J. Cros; Y. Lefèvre; M. Lajoie-Mazenc	[View] [Download]
Abstract: Nowadays, powerful tools enable to simulate the werk of inverter fed machine systems. But, they generally require long calculation times and large memory capacities and many parameters. So, they are not well adapted for an iterative design. In this paper, we present an efficient model, based on optimization techniques, for current fed synchronous machines fed by means of current controlled voltage inverter which leads to very short calculation times to determine torque speed characteristic of such an actuator. The limits of the valitidy of this model are discussed and simulated results are compared to experimental ones for validation.

	A TORQUE CONTROL STRATEGY FOR MOTOR STARTERS By Hung T. Nguyen; Frank Bartolo	[View] [Download]
Abstract: In heavy industries such as coal mining or quarry products, solid-state motor starters for induction motors have been used extensively to bring conveyor systems to full speed because of their softstart capability. A major problem for industrial motor starters using the standard voltage ramping technique is that they usually experience inconsistent overall motor run-up time and instability near full speed. Current industrial solutions for this problem require the use of current feedback or tacho feedback. In this paper, we show that the standard voltage ramp currently used in industrial motor starters does not correlate to the run-up time, nor guarantees substantial eduction of torque and current surges. Digital implementation of a voltage ramping power starter indeed confirms the validity of these results. A torque-control strategy is then proposed for motor starter which would provide substantial reduction of torque and current surges, at the same time would guarantee the required run-up time of the induction motor without the use of a tacho-generator. Experimental results show that an effective torque-controlled power starter can be implemented successfully.

	A NOVEL VOLTS / HERTZ CONTROL METHOD FOR AN INDUCTION MOTOR TO IMPROVE THE TORQUE CHARACTERISTICS IN THE LOW SPEED RANGE By T. Kataoka; Y. Sato; A. Bendiabdellah	[View] [Download]
Abstract: The volts/hertz controlled induction motors are widely used in industries because of their simple control system configurations. In such motors the influence of stator resistance drop becomes large in the low speed range, and compensation of this voltage drop is necessary to prevent a decrease in the developed torque. In this paper a novel volts/hertz control method to improve the torque characteristics in the low speed range is presented. This method is based on on-line calculation of rotor flux information from the reactive power of the motor. The calculated result is controlled so as to coincide with its reference signal. As a result, a linear torque to slip frequency characteristic is obtained. Since no knowledge of stator resistance is required, the torque characteristics become insensitive to stator resistance variations due to temperature variations. Experimental results are included to confirm the effectiveness of the proposed control method.

	INTELLIGENT DRIVES IN SYSTEMS WITH DECENTRALIZED INTELLIGENCE By R. Schönfeld; M. Franke; H. Hasan; F. Müller	[View] [Download]
Abstract: An opportunity to substitute mechanical gear systems in packaging machines by a system of intelligent single drives in order to get more flexibility will be presented in this paper. The single drives are coupled via a serial bus. Starting from a definition of basic functions of an intelligent drive, a practical realization will be presented. This section includes a short description of the used control structure, a possibility of reference generation and the used thermal model for monitoring the drive temperature too. The features of the bus system used for the coupling of the drives are discussed in a following section. Tools for the description of such a drive system are necessary for its design, simulation and starting up and can be based e.g. on a function chart. Last but not least a pouch-, form-, fill- and seal-machine equipped with a system of intelligent single drives is presented.

	HIGH EFFICIENCY, LONG LIFE ACTUATOR FOR PV WATER PUMPING APPLICATIONS By R. Liebenberg; J. H. R. Enslin; F. S. van der Merwe	[View] [Download]
Abstract: In practise, a typical diaphragm configuration, photovoltaic (PV) water pumping system consists of a DC permanent magnet motor driving a diaphragm pump via a cam. The typical efficiency is low and its life span short compared to that of the average solar cell. A better solution to the problems of low cost PV water pumping systems with low flow rates is introduced. The use of a linear DC motor or actuator as drive is suggested. A higher efficiency and life expectancy can be achieved for it has less friction and no cam losses. The aims of the project were to establish the required thrust force and stroke length, evaluate possible electromagnetic configurations by making use of a Finite Element Analysis (FEA) package and finally to evaluate different electromechanical options. The results obtained for these criteria will be discussed concluding with a choice of the best topology.

	AN IDEAL PWM-VSI INVERTER WITH FEEDFORWARD AND FEEDBACK COMPENSATION By John K. Pedersen; Frede Blaabjerg; Johnny W. Jensen; Paul Thogersen	[View] [Download]
Abstract: This paper presents different compensation techniques based on feedforward and feedback techniques for obtaining an ideal PWM-VSI inverter to AC-machines. Unlinearities like blanking-time, voltage drop across the power devices and DC-link voltage ripple cause torque and speed fluctuations in the AC-machine. Different techniques are proposed and tested for eliminating these unlinearities. The blanking-time compensation is done by both a phase current feedforward and a voltage vector feedback. The voltage drop compensation is realized with a current feedforward and finally the DC-link voltage ripple is compensated by a feedforward of the measured DC-link voltage. A comparison and the influence of the different compensation technique are done on a 16-bit microcontroller based PWM-VSI inverter. Test results show a significant improved performance of the AC-machine at no load and at low speed when the compensation techniques are used.

	VECTOR CONTROLLED DRIVES IN A STEEL PROCESSING APPLICATION By R. Jones; W. Wymeersch; P. Lataire	[View] [Download]
Abstract: A Belgian sheet steel manufacturer has specified a new range of a.c. variable speed drives as part of the upgrading of a discontinuous tandem cold mill (TCM) to a continuous process coupled with the preceding pickle line. The conversion of the TCM required the inclusion of a continuous exit section consisting mainly of d.c. driven tension reels and flying shear. Four quadrant, line regenerative, a.c. vector controlled drives have been selected to meet the performance requirement of the associated pinch, deflector and shape measuring rolls, necessary during an automatic reel changeover at 250 metres per minute and during the rapid controlled stopping duty. The small size of the induction motors, for the required overload torque rating, and the dynamic performance possibilities offered by these latest 4 quadrant drives were factors influencing the choice for this exacting application. The paper will focus on the performance capabilities of induction motors in developing overload torques of many times their full load rating for rapid speed changes. Comparisons will be made between the calculated results from equivalent circuit models of the induction motors and measurements taken from production equipments. A brief description of the other features incorporated into this range of a.c. drives gives an insight into the potential that such products offer for a wide range of high performance applications.