EPE Association: EPE 1989 - 36 - Dialogue Session 2.3: ADJUSTABLE SPEED DRIVES

EPE 1989 - 36 - Dialogue Session 2.3: ADJUSTABLE SPEED DRIVES
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   OPTIMAL EFFICIENCY CONTROL FOR ENERGY SAVING OF VARIABLE SPEED AC MOTOR
By Hideo Tomita; Shao-jun Zheng; Toshimasa Haneyoshi; Osamu Miyashita; Akeshi Maeda [View]
[Download]

Abstract: The paper describes a simple but effective method for energy saving of an induction motor driven by a general-purpose sinusoidally pulse-width-modulated (PWM) inverter. The method is based on efficiency control with the proposed voltage-current pattern to keep optimal efficiency of the variable speed AC motor having a light load or on-and-off load. The voltage-current pattern is easily desinged by using the motor equivalent circuit. The experimental results on a three-phase cagetype induction motor confirms sufficient efficiency improvement and usefulness of the method.

   FUNDAMENTALS FOR THE DESIGN OF HIGH SPEED INDUCTION MOTOR DRIVES WITH TRANSISTOR INVERTER SUPPLY
By E. Ch. Andresen; R. Pfeiffer; L. Werth [View]
[Download]

Abstract: High speed induction motors with frequency control are increasingly applied on industrial drives, e.g. on high speed milling machines, compressors etc. The maximum power output and the speed as well are limited by increasing power losses and heating of the machine. The paper presents the results of comprehensive measurements and calculations considering different supply modes (sine wave, six step, PWM), different lengths of the motor air gap and different rotor designs. A novel calculation method for the inverter induced core losses is described. Suggestions for design and control of transistorized high speed induction motor drives are derived.

   SYNTHESIS OF ACTIVE AND REACTIVE POWER CONTROLLERS FOR THE SLIP POWER RECOVERY DRIVE
By G. D. Marques [View]
[Download]

Abstract: The Slip Power Recovery Drive (SPRD) can be employed as a "Variable Speed, Constant Frequency" Generator in the exploitation of some renewable energies, like the Wind Energy, the Sea Wave Energy among others. The use of a thyristor bridge in the Slip Power Converter, just allows the control of the active power. The replacement of this thyristor bridge by a GTO converter with phase shift and PWM switching, allows the control of both the active and the reactive power within certain limits. This paper presents the synthesis of the active and reactive power controllers that may be used to control the SPRD in the above mentioned applications.

   INDUSTRIAL DRIVE WITH INTEGRATED POSITION CONTROL
By Rupert Weber [View]
[Download]

Abstract: This paper describes an industrial drive inverter with integrated position control. The position and speed controller are designed completely in digital technique. This enables offset-free drive operations. All set up operations are menue driven. The knowledge of a programming language is not necessary. Built-in service functions support the start-up operation. This paper presents the control structure and the performance of this drive.

   COMMON BASIC CONTROL ELEMENTS FOR DIFFERENT CONVERTER SYSTEMS IN INDUSTRIAL VARIABLE-SPEED DRIVES
By F. W. Fuchs [View]
[Download]

Abstract: Converters for industrial variable-speed drives are usually equipped with type-specific control schemes. The control schemes of four different converter systems are analyzed in their basic design. Monitoring and operator control are not considered. It is found that these schemes consist of both common usable basic control elements and type-specific basic control elements. For demonstration, a hypothetic common control scheme for the four drive systems analyzed is set up, comprising these basic control elements. It can be seen that, when applying the common usable basic control elements, a simplified overall design and realization of the control equipment for the four converter systems under consideration is possible. For that purpose, the common basic control elements have to be realized in the same hardware and with the same software. Differences between the systems, i.e. the system specific control elements, should only be made where it is necessary.

   COMPARISON OF SEVERAL CONTROL SCHEMES FOR AC INDUCTION MOTORS UNDER STEADY STATE AND DYNAMIC CONDITIONS
By G. Heinemann [View]
[Download]

Abstract: In order to examine the possible use of different control schemes for AC induction motors, a comparison of the following methods was made:
- field orientated control
- control with given voltage to stator frequency charaderistic (Us / f1)
- control with impressed stator currents and open-loop flux control (Is / f2) and a new
- control scheme, proposed by R. Jönsson.
The comparison is made using the same hardware equipment for an AC induction motor, inverter and microcomputer for control and includes the behaviour under steady state conditions at different speeds and loads, the sensitivity against variation in parameters of the induction motor and the dynamic behaviour at change of speed reference and mechanical load. Some of the measured results are clearified by computer simulation.

   INFLUENCE OF THE ELASTIC COUPLING ON THE CONTROL OF CONVERTER FED DC MOTOR DRIVES
By W. Hulsbosch; P. Cornelissen; R. Reekmans; A. Vandenput; W. Geysen [View]
[Download]

Abstract: In many DC drive systems, there is an elastic coupling between the motor and the load. However, this elastic coupling deteriorates the dynamic properties of the system, because the multiplication factor of the speed regulator has to be lowered for stability reasons. The dynamic respons of the load can be upgraded through a feedback of the speed difference between motor and load with a certain multiplication factor, as a correction on the current command. In this method, the feedback of the speed of the load instead of the motor is possible, giving better dynamic properties. However, because of the additional feedback the simple optimalisation method of the Symmetrical Optimum cannot be applied. In this paper an optimalisation procedure based on the Method of Double Ratios (P. Naslin 1968) is proposed. Both the parameters of the speed regulator and the multiplication factor of the speed difference are determined.

   ACCURATE CONTROL MODELS FOR THREE-PHASE MACHINES, INCLUDING MEASURES TO AVOID RIPPLE-(HARMONIC-)TORQUES
By H. Mijnarends; W. Deleroi [View]
[Download]

Abstract: Futher research on the models presented at EPE '87. We found simple accurate control models of 3-phase drives and simple methods to avoid ripple-(harmonic-)torques. Using the theory of multi-variable control-systems, it is possible to use seperate control circuits: one for position-(speed-)control, including torque, and one for flux-correction. Condition is to apply step-function-responses without any (oscillating) overshoot. Ripple-torque and ripple-speed disturbes often the control system. Simple matches between machine and power-electronics and adequate lay-out of the machine solves these problems. Important items have been tested.

   CONTROL LAWS OF A SYNCHRONOUS MACHINE FED BY A PWM VOLTAGE SOURCE INVERTER
By Maurice Fadel; Bernard de Fornel [View]
[Download]

Abstract: The introduction of a micro-processor into a command loop permits us to envisage new control structures. In line with this, we propose to set up modern adjusters to control the electro-magnetic torque in the synchronous machine fed by a PMW inverter. The first technique, called STATE SPACE FEEDBACK, consists in decomposing the dynamics of the procedure into two time scales, and in giving a reduced-order action model. This reduced-state model serve as a base for the construction of a dynamic flux observer. We next develop a state space feedback allowing control of the transitory evolution of state variables in a speed variator. The second technique, called ADAPTIV CONTROL, is concerned with setting-up an self tunning regulator ensuring adaptation of the regulator's parameters at the function point. This technique requires a line identification procedure which permits knowledge of the different coefficients of the equivalent-transfer function.

   A CONTINUOUS-DISCRETE TIME STATE ESTIMATOR FOR A SYNCHRONOUS MOTOR FED BY PWM INVERTER
By S. Liu; M. Stiebler [View]
[Download]

Abstract: In order to control PWM-fed synchronous motor drives with high dynamics, an accurate knowledge of the machine state variables in the whole range of operation is necessary. A method is presented to estimate these quantities by using electrical signals only (stator currents, stator voltages and excitation current), which can be measured easily. The mathematical modeling is discussed. A recursive filter algorithm based on the so-called extended Kalman filter technique is given. The good performance of the presented estimation method is demonstrated by computer simulation results. The proposed algorithm is suitable to be implemented with a fast microprocessor system for on-line operation.

   STUDY OF CONTROL STRATEGIES AND REGULATION IN CYCLOCONVERTER FED SYNCHRONOUS MACHINES
By H. Huang; B. Davat; M. Lajoie-Mazenc [View]
[Download]

Abstract: In this paper the authors compare the methods of current regulation and the control strategies for a cycloconverter-fed synchronous machine. Different methods are implemented in a simulation process of the whole system in order to show how the best torque response can be obtained in the case of a salient pole machine equipped with damper circuits.

   SIMULATION STUDY OF DYNAMICS OF CURRENT-CONTROLLED DOUBLY-FED INDUCTION MACHINE
By A. M. Walczyna; W. Koczara [View]
[Download]

Abstract: The paper presents results of computer simulation of dynamics of current-controlled doubly-fed induction machine. The machine is controlled in perpendicular axes oriented by a stator voltage vector. A structure of the machine and of the control system is presented. Torque and stator reactive power are chosen as output variables. Transients in output variables fluxes and in currents during rapid reference speed, load and rotor reactive current co-ordinate changes are plotted. Similar plot illustrating the dynamic behaviour of the system during rapid stator voltage changes is quoted. Dependance of torque and of stator reactive power on rotor current co-ordinates is examined. High overload capacity of the system is shown. Sample experimental results are compared with simulation ones.

EPE 1989 - 36 - Dialogue Session 2.3: ADJUSTABLE SPEED DRIVES
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1989 - Conference > EPE 1989 - 36 - Dialogue Session 2.3: ADJUSTABLE SPEED DRIVES
	[return to parent folder]

	OPTIMAL EFFICIENCY CONTROL FOR ENERGY SAVING OF VARIABLE SPEED AC MOTOR By Hideo Tomita; Shao-jun Zheng; Toshimasa Haneyoshi; Osamu Miyashita; Akeshi Maeda	[View] [Download]
Abstract: The paper describes a simple but effective method for energy saving of an induction motor driven by a general-purpose sinusoidally pulse-width-modulated (PWM) inverter. The method is based on efficiency control with the proposed voltage-current pattern to keep optimal efficiency of the variable speed AC motor having a light load or on-and-off load. The voltage-current pattern is easily desinged by using the motor equivalent circuit. The experimental results on a three-phase cagetype induction motor confirms sufficient efficiency improvement and usefulness of the method.

	FUNDAMENTALS FOR THE DESIGN OF HIGH SPEED INDUCTION MOTOR DRIVES WITH TRANSISTOR INVERTER SUPPLY By E. Ch. Andresen; R. Pfeiffer; L. Werth	[View] [Download]
Abstract: High speed induction motors with frequency control are increasingly applied on industrial drives, e.g. on high speed milling machines, compressors etc. The maximum power output and the speed as well are limited by increasing power losses and heating of the machine. The paper presents the results of comprehensive measurements and calculations considering different supply modes (sine wave, six step, PWM), different lengths of the motor air gap and different rotor designs. A novel calculation method for the inverter induced core losses is described. Suggestions for design and control of transistorized high speed induction motor drives are derived.

	SYNTHESIS OF ACTIVE AND REACTIVE POWER CONTROLLERS FOR THE SLIP POWER RECOVERY DRIVE By G. D. Marques	[View] [Download]
Abstract: The Slip Power Recovery Drive (SPRD) can be employed as a "Variable Speed, Constant Frequency" Generator in the exploitation of some renewable energies, like the Wind Energy, the Sea Wave Energy among others. The use of a thyristor bridge in the Slip Power Converter, just allows the control of the active power. The replacement of this thyristor bridge by a GTO converter with phase shift and PWM switching, allows the control of both the active and the reactive power within certain limits. This paper presents the synthesis of the active and reactive power controllers that may be used to control the SPRD in the above mentioned applications.

	INDUSTRIAL DRIVE WITH INTEGRATED POSITION CONTROL By Rupert Weber	[View] [Download]
Abstract: This paper describes an industrial drive inverter with integrated position control. The position and speed controller are designed completely in digital technique. This enables offset-free drive operations. All set up operations are menue driven. The knowledge of a programming language is not necessary. Built-in service functions support the start-up operation. This paper presents the control structure and the performance of this drive.

	COMMON BASIC CONTROL ELEMENTS FOR DIFFERENT CONVERTER SYSTEMS IN INDUSTRIAL VARIABLE-SPEED DRIVES By F. W. Fuchs	[View] [Download]
Abstract: Converters for industrial variable-speed drives are usually equipped with type-specific control schemes. The control schemes of four different converter systems are analyzed in their basic design. Monitoring and operator control are not considered. It is found that these schemes consist of both common usable basic control elements and type-specific basic control elements. For demonstration, a hypothetic common control scheme for the four drive systems analyzed is set up, comprising these basic control elements. It can be seen that, when applying the common usable basic control elements, a simplified overall design and realization of the control equipment for the four converter systems under consideration is possible. For that purpose, the common basic control elements have to be realized in the same hardware and with the same software. Differences between the systems, i.e. the system specific control elements, should only be made where it is necessary.

	COMPARISON OF SEVERAL CONTROL SCHEMES FOR AC INDUCTION MOTORS UNDER STEADY STATE AND DYNAMIC CONDITIONS By G. Heinemann	[View] [Download]
Abstract: In order to examine the possible use of different control schemes for AC induction motors, a comparison of the following methods was made: - field orientated control - control with given voltage to stator frequency charaderistic (Us / f1) - control with impressed stator currents and open-loop flux control (Is / f2) and a new - control scheme, proposed by R. Jönsson. The comparison is made using the same hardware equipment for an AC induction motor, inverter and microcomputer for control and includes the behaviour under steady state conditions at different speeds and loads, the sensitivity against variation in parameters of the induction motor and the dynamic behaviour at change of speed reference and mechanical load. Some of the measured results are clearified by computer simulation.

	INFLUENCE OF THE ELASTIC COUPLING ON THE CONTROL OF CONVERTER FED DC MOTOR DRIVES By W. Hulsbosch; P. Cornelissen; R. Reekmans; A. Vandenput; W. Geysen	[View] [Download]
Abstract: In many DC drive systems, there is an elastic coupling between the motor and the load. However, this elastic coupling deteriorates the dynamic properties of the system, because the multiplication factor of the speed regulator has to be lowered for stability reasons. The dynamic respons of the load can be upgraded through a feedback of the speed difference between motor and load with a certain multiplication factor, as a correction on the current command. In this method, the feedback of the speed of the load instead of the motor is possible, giving better dynamic properties. However, because of the additional feedback the simple optimalisation method of the Symmetrical Optimum cannot be applied. In this paper an optimalisation procedure based on the Method of Double Ratios (P. Naslin 1968) is proposed. Both the parameters of the speed regulator and the multiplication factor of the speed difference are determined.

	ACCURATE CONTROL MODELS FOR THREE-PHASE MACHINES, INCLUDING MEASURES TO AVOID RIPPLE-(HARMONIC-)TORQUES By H. Mijnarends; W. Deleroi	[View] [Download]
Abstract: Futher research on the models presented at EPE '87. We found simple accurate control models of 3-phase drives and simple methods to avoid ripple-(harmonic-)torques. Using the theory of multi-variable control-systems, it is possible to use seperate control circuits: one for position-(speed-)control, including torque, and one for flux-correction. Condition is to apply step-function-responses without any (oscillating) overshoot. Ripple-torque and ripple-speed disturbes often the control system. Simple matches between machine and power-electronics and adequate lay-out of the machine solves these problems. Important items have been tested.

	CONTROL LAWS OF A SYNCHRONOUS MACHINE FED BY A PWM VOLTAGE SOURCE INVERTER By Maurice Fadel; Bernard de Fornel	[View] [Download]
Abstract: The introduction of a micro-processor into a command loop permits us to envisage new control structures. In line with this, we propose to set up modern adjusters to control the electro-magnetic torque in the synchronous machine fed by a PMW inverter. The first technique, called STATE SPACE FEEDBACK, consists in decomposing the dynamics of the procedure into two time scales, and in giving a reduced-order action model. This reduced-state model serve as a base for the construction of a dynamic flux observer. We next develop a state space feedback allowing control of the transitory evolution of state variables in a speed variator. The second technique, called ADAPTIV CONTROL, is concerned with setting-up an self tunning regulator ensuring adaptation of the regulator's parameters at the function point. This technique requires a line identification procedure which permits knowledge of the different coefficients of the equivalent-transfer function.

	A CONTINUOUS-DISCRETE TIME STATE ESTIMATOR FOR A SYNCHRONOUS MOTOR FED BY PWM INVERTER By S. Liu; M. Stiebler	[View] [Download]
Abstract: In order to control PWM-fed synchronous motor drives with high dynamics, an accurate knowledge of the machine state variables in the whole range of operation is necessary. A method is presented to estimate these quantities by using electrical signals only (stator currents, stator voltages and excitation current), which can be measured easily. The mathematical modeling is discussed. A recursive filter algorithm based on the so-called extended Kalman filter technique is given. The good performance of the presented estimation method is demonstrated by computer simulation results. The proposed algorithm is suitable to be implemented with a fast microprocessor system for on-line operation.

	STUDY OF CONTROL STRATEGIES AND REGULATION IN CYCLOCONVERTER FED SYNCHRONOUS MACHINES By H. Huang; B. Davat; M. Lajoie-Mazenc	[View] [Download]
Abstract: In this paper the authors compare the methods of current regulation and the control strategies for a cycloconverter-fed synchronous machine. Different methods are implemented in a simulation process of the whole system in order to show how the best torque response can be obtained in the case of a salient pole machine equipped with damper circuits.

	SIMULATION STUDY OF DYNAMICS OF CURRENT-CONTROLLED DOUBLY-FED INDUCTION MACHINE By A. M. Walczyna; W. Koczara	[View] [Download]
Abstract: The paper presents results of computer simulation of dynamics of current-controlled doubly-fed induction machine. The machine is controlled in perpendicular axes oriented by a stator voltage vector. A structure of the machine and of the control system is presented. Torque and stator reactive power are chosen as output variables. Transients in output variables fluxes and in currents during rapid reference speed, load and rotor reactive current co-ordinate changes are plotted. Similar plot illustrating the dynamic behaviour of the system during rapid stator voltage changes is quoted. Dependance of torque and of stator reactive power on rotor current co-ordinates is examined. High overload capacity of the system is shown. Sample experimental results are compared with simulation ones.