EPE Association: EPE 1997 – 83: Dialogue Session DS5g: SENSORLESS DRIVES

EPE 1997 – 83: Dialogue Session DS5g: SENSORLESS DRIVES - INDUCTION MACHINES
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1997 - Conference > EPE 1997 – 83: Dialogue Session DS5g: SENSORLESS DRIVES - INDUCTION MACHINES

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   ROBUST CONTROL OF SENSORLESS VECTOR CONTROL DRIVES
By R. Blasco-Gimenez; F. Morant [View]
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Abstract: Sensorless vector control drives rely on a machine model for speed estimation. When high dynamic performance is to be obtained, the closed loop system might exhibit unstable operation. Due to the non-linear nature of the drive, this unstability is such that can appear in response to changes in load, speed and machine parameters. This paper introduces the idea of a supervisory level for sensorless induction motor drives to provide robust operation and high dynamic performance regardless of the drive operating condition. The supervisory level will be implemented using a fuzzy inference system.

   A MICROCONTROLLER IMPLEMENTATION OF SPEED SENSORLESS FIELD ORIENTED CONTROL OF INDUCTION MACHINE
By Martin Riese [View]
[Download]

Abstract: Speed-sensorless field oriented control of an induction motor is implemented on a 16-bit micro-controller using the machine as a reference model for a speed adaptation algorithm. The combination with a flux observer allows to determine adaptation parameters and improves robustness in the area of low stator frequencies, compared to a feed-forward flux model. Thus, good performance is achieved even in the very low speed region. To ensure field orientation around zero stator frequency, an additional algorithm based on the magnetic saturation of the motor is proposed.

   A NOVEL SENSORLESS CONTROLLER FOR INDUCTION MOTOR DRIVES
By Shyh-Shing Pemg; Yen-Shin Lai; Chang-Huan Liu [View]
[Download]

Abstract: A novel sensorless controller based on model reference adaptive system (MRAS) for induction motor drives will be presented in this paper. In comparison with previous reports [1-2] which involves temperature-sensitive parameters, including rotor and/or stator resistors, the proposed control method requires neither rotor time constant nor stator resistance in both adjustable and reference models. Moreover, since no integral operation is required, the method provides wider bandwidth for speed control. Simulation and experimental results are presented to confirm the theoretical analysis.

   CONTROL OF A SHAFT-SENSORLESS POSITION INDUCTION MOTOR USING AN ASYMMETRIC OUTER-SECTION CAGE
By J. Cilia; G. M. Asher; K. J. Bradley; M. Sumner [View]
[Download]

Abstract: This paper describes a method of obtaining a rotor position signal from a cage induction machine operating without a mechanical shaft-sensor and reviews the vector control schemes suitable for position control. The position detection is based on introducing a circumferential variation in the resistance of a high resistance outer section cage of an induction machine rotor. The paper describes an implementation of the method for a 30kW double cage machine having variable gauge copper wire in the outer slots. It is shown that the present degree of asymmetry in the cage resistance results in position control up to 50% load before non-linear saturation effects degrade control performance. Increasing asymmetry is possible but consideration must be given to the presence of asymmetry-induced torque ripple. The paper describes vector control schemes to reduce the torque ripple and discusses the research required for a complete engineering solution.

   Implementation of a Sensorless Induction Motor Drive Control System with Prescribed Closed-Loop Rotor Magnetic Flux and Speed Dynamics
By Stephen J. Dodds; Jan Vittek; Martin Mienkina [View]
[Download]

Abstract: This paper briefly describes the theory and presents experimental results of a new method for control of electric drives with induction motors. Control of the rotor magnetic flux norm and angular velocity is achieved without measurements from sensors mounted on the output shaft. The dynamic responses of both the controlled variables are of the first order with time constants chosen by the drive user to snit the particular application. The experimental results presented show good agreement with theoretical conclusions and simulation results published previously.

   A PCMCIA DSP-CARD TO BOOST INVERTER PERFORMANCE: SENSORLESS DRIVE CONTROL VIA EXTENDED KALMAN FILTER
By Eckart von Westerholt [View]
[Download]

Abstract: A PCMCIA card to be used as an optional control module is described. Integrating a fast, C-programmable floating point digital signal processor (DSP), its design as an optional control card for existing inverters meets two major objectives: First, it represents a very flexible development tool for the real-time implementation of new control algorithms, and second, it allows to offer application-specific or high performance options with a very short time-to-market delay. As application example, a speed-sensorless control of ac-drives is proposed. Based on the nonlinear machine model, a 6th order Extended Kalman Filter (EKF) has been implemented to observe the motor state variables including the load torque. Both the observer and a direct field-oriented linearizing regulatory control are programmed exclusively in C and simply recompiled with the option's card base program. A very satisfactory overall performance has been obtained with standard (commercialized) inverters. Experimental results of 4kW and 55kW drives are discussed.

   REAL-TIME SENSORLESS CONTROL FOR ROTOR FIELD ORIENTED INDUCTION MOTOR
By Dragos Ovidiu Kisch; Mariau Ghinea; Gabriel Sirbu; Mariana Kisch [View]
[Download]

Abstract: The paper describes a new and rigorous mathematical model for the rotor field oriented system with induction motor which use the estimated speed and rotor flux based on a Model Reference Adaptive Control, as well as the real-time approach. The estimated speed and rotor flux are used for the speed and flux feedback control. The stability and the convergence of the estimator is improved on the basis of hyperstability theory fur non-linear systems. The real-time controller and estimator are realized with a high-speed acquisition card Keithley - DAS - 1600 and a PC/Pentium computer. The simulated results are compared with the corresponding one obtained experimentally, to prove this mathematical model.

   Sensorless Vector Control of Induction Machines with Stator Voltage Offset Compensation
By Yukio Kataoka; Hisao Kubota; Kouki Matsuse [View]
[Download]

Abstract: The vector control method is widely used for induction machine drives. Recently, sensorless vector control for induction machine has been investigated and proposed. The speed range for the drives is limited to about I: I 00 in industry. The main reason is the inaccuracy of stator voltage measurement. The lower rotor speed becomes, the lower stator voltage is. Therefore, it is difficult to detect the stator voltage accurately in the lower speed region. This paper presents a method of improving the low speed performance of sensorless vector controlled induction machines by compensating the stator voltage offset. Also, the validity of the proposed method is verified by experimentation.

   FIELD ORIENTED CONTROL OF INDUCTION MOTOR WITHOUT SPEED SENSOR
By M. Hövermann; B. Orlik; U. Schumacher [View]
[Download]

Abstract: The field oriented control of induction motor drives without a mechanical sensor requires the calculation of the flux and the speed in a model from the voltages and currents of the motor. In case of a faulty estimation of the flux angle, i.e. due to incorrect model parameters, the stability of the system is at risk. In this paper a method is proposed to identify and correct a wrong flux angle in the model, thus ensuring a stable behaviour of the sensorless controlled drive.

   SENSITIVTY ANALYSIS OF SENSORLESS INDUCTION MOTOR DRIVE TO MOTOR PARAMETER CHANGES
By Teresa Orlowska-Kowalska; Piotr Wojsznis [View]
[Download]

Abstract: Motor drives with speed sensors are expensive and less reliable. Therefore there is a big interest in finding software-based methods of controlling the induction motors using only the stator current and voltage sensors. This paper shows the analysis of flu.x observer and sensorless drive sensitivity to motor parameter changes such as Rr, Rs, Xr and Xs.

   DSP Implementation of an AC-Machine Sensorless Speed Measurement System Using the Wigner Distribution
By José A. Restrepo; Trina A. de Perez; Maria I. Gimenez de Guzman; Victor M. Guzman [View]
[Download]

Abstract: The robustness of the variable speed driver, based on AC machines, is lost with the inclusion of shaft mounted speed sensors. This calls for a method to estimate or measuring the machine speed without using sensors coupled to the machine shaft. In this work a DSP implementation of Time-Frequency (TF) based methods for real time measurement of the AC machine speed is presented. The proposed implementation is based on the Wigner Distribution (WD).

EPE 1997 – 83: Dialogue Session DS5g: SENSORLESS DRIVES - INDUCTION MACHINES
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1997 - Conference > EPE 1997 – 83: Dialogue Session DS5g: SENSORLESS DRIVES - INDUCTION MACHINES
	[return to parent folder]

	ROBUST CONTROL OF SENSORLESS VECTOR CONTROL DRIVES By R. Blasco-Gimenez; F. Morant	[View] [Download]
Abstract: Sensorless vector control drives rely on a machine model for speed estimation. When high dynamic performance is to be obtained, the closed loop system might exhibit unstable operation. Due to the non-linear nature of the drive, this unstability is such that can appear in response to changes in load, speed and machine parameters. This paper introduces the idea of a supervisory level for sensorless induction motor drives to provide robust operation and high dynamic performance regardless of the drive operating condition. The supervisory level will be implemented using a fuzzy inference system.

	A MICROCONTROLLER IMPLEMENTATION OF SPEED SENSORLESS FIELD ORIENTED CONTROL OF INDUCTION MACHINE By Martin Riese	[View] [Download]
Abstract: Speed-sensorless field oriented control of an induction motor is implemented on a 16-bit micro-controller using the machine as a reference model for a speed adaptation algorithm. The combination with a flux observer allows to determine adaptation parameters and improves robustness in the area of low stator frequencies, compared to a feed-forward flux model. Thus, good performance is achieved even in the very low speed region. To ensure field orientation around zero stator frequency, an additional algorithm based on the magnetic saturation of the motor is proposed.

	A NOVEL SENSORLESS CONTROLLER FOR INDUCTION MOTOR DRIVES By Shyh-Shing Pemg; Yen-Shin Lai; Chang-Huan Liu	[View] [Download]
Abstract: A novel sensorless controller based on model reference adaptive system (MRAS) for induction motor drives will be presented in this paper. In comparison with previous reports [1-2] which involves temperature-sensitive parameters, including rotor and/or stator resistors, the proposed control method requires neither rotor time constant nor stator resistance in both adjustable and reference models. Moreover, since no integral operation is required, the method provides wider bandwidth for speed control. Simulation and experimental results are presented to confirm the theoretical analysis.

	CONTROL OF A SHAFT-SENSORLESS POSITION INDUCTION MOTOR USING AN ASYMMETRIC OUTER-SECTION CAGE By J. Cilia; G. M. Asher; K. J. Bradley; M. Sumner	[View] [Download]
Abstract: This paper describes a method of obtaining a rotor position signal from a cage induction machine operating without a mechanical shaft-sensor and reviews the vector control schemes suitable for position control. The position detection is based on introducing a circumferential variation in the resistance of a high resistance outer section cage of an induction machine rotor. The paper describes an implementation of the method for a 30kW double cage machine having variable gauge copper wire in the outer slots. It is shown that the present degree of asymmetry in the cage resistance results in position control up to 50% load before non-linear saturation effects degrade control performance. Increasing asymmetry is possible but consideration must be given to the presence of asymmetry-induced torque ripple. The paper describes vector control schemes to reduce the torque ripple and discusses the research required for a complete engineering solution.

	Implementation of a Sensorless Induction Motor Drive Control System with Prescribed Closed-Loop Rotor Magnetic Flux and Speed Dynamics By Stephen J. Dodds; Jan Vittek; Martin Mienkina	[View] [Download]
Abstract: This paper briefly describes the theory and presents experimental results of a new method for control of electric drives with induction motors. Control of the rotor magnetic flux norm and angular velocity is achieved without measurements from sensors mounted on the output shaft. The dynamic responses of both the controlled variables are of the first order with time constants chosen by the drive user to snit the particular application. The experimental results presented show good agreement with theoretical conclusions and simulation results published previously.

	A PCMCIA DSP-CARD TO BOOST INVERTER PERFORMANCE: SENSORLESS DRIVE CONTROL VIA EXTENDED KALMAN FILTER By Eckart von Westerholt	[View] [Download]
Abstract: A PCMCIA card to be used as an optional control module is described. Integrating a fast, C-programmable floating point digital signal processor (DSP), its design as an optional control card for existing inverters meets two major objectives: First, it represents a very flexible development tool for the real-time implementation of new control algorithms, and second, it allows to offer application-specific or high performance options with a very short time-to-market delay. As application example, a speed-sensorless control of ac-drives is proposed. Based on the nonlinear machine model, a 6th order Extended Kalman Filter (EKF) has been implemented to observe the motor state variables including the load torque. Both the observer and a direct field-oriented linearizing regulatory control are programmed exclusively in C and simply recompiled with the option's card base program. A very satisfactory overall performance has been obtained with standard (commercialized) inverters. Experimental results of 4kW and 55kW drives are discussed.

	REAL-TIME SENSORLESS CONTROL FOR ROTOR FIELD ORIENTED INDUCTION MOTOR By Dragos Ovidiu Kisch; Mariau Ghinea; Gabriel Sirbu; Mariana Kisch	[View] [Download]
Abstract: The paper describes a new and rigorous mathematical model for the rotor field oriented system with induction motor which use the estimated speed and rotor flux based on a Model Reference Adaptive Control, as well as the real-time approach. The estimated speed and rotor flux are used for the speed and flux feedback control. The stability and the convergence of the estimator is improved on the basis of hyperstability theory fur non-linear systems. The real-time controller and estimator are realized with a high-speed acquisition card Keithley - DAS - 1600 and a PC/Pentium computer. The simulated results are compared with the corresponding one obtained experimentally, to prove this mathematical model.

	Sensorless Vector Control of Induction Machines with Stator Voltage Offset Compensation By Yukio Kataoka; Hisao Kubota; Kouki Matsuse	[View] [Download]
Abstract: The vector control method is widely used for induction machine drives. Recently, sensorless vector control for induction machine has been investigated and proposed. The speed range for the drives is limited to about I: I 00 in industry. The main reason is the inaccuracy of stator voltage measurement. The lower rotor speed becomes, the lower stator voltage is. Therefore, it is difficult to detect the stator voltage accurately in the lower speed region. This paper presents a method of improving the low speed performance of sensorless vector controlled induction machines by compensating the stator voltage offset. Also, the validity of the proposed method is verified by experimentation.

	FIELD ORIENTED CONTROL OF INDUCTION MOTOR WITHOUT SPEED SENSOR By M. Hövermann; B. Orlik; U. Schumacher	[View] [Download]
Abstract: The field oriented control of induction motor drives without a mechanical sensor requires the calculation of the flux and the speed in a model from the voltages and currents of the motor. In case of a faulty estimation of the flux angle, i.e. due to incorrect model parameters, the stability of the system is at risk. In this paper a method is proposed to identify and correct a wrong flux angle in the model, thus ensuring a stable behaviour of the sensorless controlled drive.

	SENSITIVTY ANALYSIS OF SENSORLESS INDUCTION MOTOR DRIVE TO MOTOR PARAMETER CHANGES By Teresa Orlowska-Kowalska; Piotr Wojsznis	[View] [Download]
Abstract: Motor drives with speed sensors are expensive and less reliable. Therefore there is a big interest in finding software-based methods of controlling the induction motors using only the stator current and voltage sensors. This paper shows the analysis of flu.x observer and sensorless drive sensitivity to motor parameter changes such as Rr, Rs, Xr and Xs.

	DSP Implementation of an AC-Machine Sensorless Speed Measurement System Using the Wigner Distribution By José A. Restrepo; Trina A. de Perez; Maria I. Gimenez de Guzman; Victor M. Guzman	[View] [Download]
Abstract: The robustness of the variable speed driver, based on AC machines, is lost with the inclusion of shaft mounted speed sensors. This calls for a method to estimate or measuring the machine speed without using sensors coupled to the machine shaft. In this work a DSP implementation of Time-Frequency (TF) based methods for real time measurement of the AC machine speed is presented. The proposed implementation is based on the Wigner Distribution (WD).