EPE Association: EPE-PEMC 2008 - Topic: Sensorless Control of Induction Motor

EPE-PEMC 2008 - Topic: Sensorless Control of Induction Motor
You are here: EPE Documents > 04 - EPE-PEMC Conference Proceedings > EPE-PEMC 2008 - Conference > EPE-PEMC 2008 - Topic: Sensorless Control of Induction Motor

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   Application of the Induction Motor Torque - Observer to the Control of Turbo - Machines
By Andrzej Dębowski [View]
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Abstract: This paper describes the results of the experiment with an application of the outer torque observer to the radial fan driven by induction motor fed from the voltage inverter. The observer is designed to be an additional standalone device connected between the induction motor and the power supply, separated from the inner signals of the inverter controller. The inputs for the observer algorithm are the three-phase currents and voltages measured in the conductors connected to the motor terminals. The output signals of this observer estimating the stator flux and motor electro-magnetic torque are used to the compressor supervisory control.

   Application of the Stator Current-Based MRAS Speed Estimator in the Sensorless Induction Motor Drive
By Mateusz Dybkowski [View]
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Abstract: The paper deals with the analysis of the vector controlled induction motor drive with a novel MRAS-type rotor speed estimator. The stability analysis method of this novel MRAS estimator is proposed. The influence of equivalent circuit parameter changes of the induction motor as well as coefficients of the adaptation algorithm of the MRAS scheme to the pole placement of the estimator transfer function and stability of the whole drive system is analysed and tested. The allowable range of motor parameter changes is determined, which guarantees the stable operation of the sensorless field oriented induction motor drive with this speed and flux estimator. Dynamical performances of the vector control system with the current-type MRAS estimator are tested in the laboratory set-up.

   Experimental Performance Evaluation for Low Speed and Regenerating Operation of Sensor-less Vector Control System of Induction Motor Using Observer Gain Tuning
By Kazuhiro Ohyama [View]
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Abstract: The design method of adaptive rotor flux observer gain to improve stability at low speed and regenerating mode was proposed in [1]. The method is based on the stability analysis. The stability analysis utilizes the linearized model considering all systems including each control loop. Therefore the proposed method considers the effects of motor constants and control circuit constants. The stability analysis using the transfer function for rotor speed considers the arrangement of pole and zero and the steady state error. The rotor flux observer gain which improves the stability for each operating condition was clarified. Also the real time tuning method of observer gain was proposed in [1]. The validity of the proposed method was confirmed on the simulation using Matlab Simulink and the experiment. Then this paper evaluates the experimental performance for low speed and regenerating operation of sensor-less vector control system of induction motor using observer gain tuning.

   Observer of Induction Motor Speed Based on Exact Disturbance Model
By Zbigniew Krzemiński [View]
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Abstract: A simplified speed observer was proposed previously by the author to estimate the rotor speed needed in control system of a drive with induction motor. Small error of estimated rotor speed was observed but errors of the stator current and rotor flux vector components appear in dependence of rotor speed. A new structure of the speed observer is proposed now with exact disturbance model and gain coefficients depending on stator frequency. The new structure was derived from the previous one by analysis of dependencies appearing in differential equations. Explanation of observer stability is presented. Properties of the proposed observer are presented using simulations of full control system.

   State and Parameter Estimation in Induction Motors using Sliding Modes
By Sachit Rao [View]
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Abstract: We present two observer based solutions to the popular problem of sensorless speed control of induction motors. The observers which provide simultaneous motor speed and flux estimation are based on the basic principles of sliding mode control theory. We present an observer, which incorporates rotor flux dynamics, that can also be used to simulataneously estimate rotor resistance (if unknown). We propose a second observer design, defined by stator flux dynamics, that is independent of the unknown rotor resistance. As for the controller of the induction motor itself, which now relies on the outputs of each observer, we propose designs again based on sliding mode control theory.

   Torque Sensorless Control of Induction Motor
By Karel Jezernik [View]
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Abstract: In this paper the torque and speed sensorless induction motor (IM) control is presented. The main idea consists in utilizing the best qualities of the both nonlinear structures of the motor observer and the current controller. Motor observer is based on flux error between modeled and measured quantities. In addition, the rotor flux observer is using combination of the feedforward and feedback terms in order to enhance the sensitivity of the observer. Torque and stator current control as well as the rotor flux observer are based on the sliding mode theory, which results in high degree of robustness towards parameters variation and the external disturbances. Proposed control scheme is implemented on DSP system extended with FPGA where event-driven current controlled modulator is realized. DSP serves for time discrete speed control and observer, while time critical current control is implemented on FPGA. Results demonstrate high efficiency of the proposed estimation and control method.

EPE-PEMC 2008 - Topic: Sensorless Control of Induction Motor
You are here: EPE Documents > 04 - EPE-PEMC Conference Proceedings > EPE-PEMC 2008 - Conference > EPE-PEMC 2008 - Topic: Sensorless Control of Induction Motor
	[return to parent folder]

	Application of the Induction Motor Torque - Observer to the Control of Turbo - Machines By Andrzej Dębowski	[View] [Download]
Abstract: This paper describes the results of the experiment with an application of the outer torque observer to the radial fan driven by induction motor fed from the voltage inverter. The observer is designed to be an additional standalone device connected between the induction motor and the power supply, separated from the inner signals of the inverter controller. The inputs for the observer algorithm are the three-phase currents and voltages measured in the conductors connected to the motor terminals. The output signals of this observer estimating the stator flux and motor electro-magnetic torque are used to the compressor supervisory control.

	Application of the Stator Current-Based MRAS Speed Estimator in the Sensorless Induction Motor Drive By Mateusz Dybkowski	[View] [Download]
Abstract: The paper deals with the analysis of the vector controlled induction motor drive with a novel MRAS-type rotor speed estimator. The stability analysis method of this novel MRAS estimator is proposed. The influence of equivalent circuit parameter changes of the induction motor as well as coefficients of the adaptation algorithm of the MRAS scheme to the pole placement of the estimator transfer function and stability of the whole drive system is analysed and tested. The allowable range of motor parameter changes is determined, which guarantees the stable operation of the sensorless field oriented induction motor drive with this speed and flux estimator. Dynamical performances of the vector control system with the current-type MRAS estimator are tested in the laboratory set-up.

	Experimental Performance Evaluation for Low Speed and Regenerating Operation of Sensor-less Vector Control System of Induction Motor Using Observer Gain Tuning By Kazuhiro Ohyama	[View] [Download]
Abstract: The design method of adaptive rotor flux observer gain to improve stability at low speed and regenerating mode was proposed in [1]. The method is based on the stability analysis. The stability analysis utilizes the linearized model considering all systems including each control loop. Therefore the proposed method considers the effects of motor constants and control circuit constants. The stability analysis using the transfer function for rotor speed considers the arrangement of pole and zero and the steady state error. The rotor flux observer gain which improves the stability for each operating condition was clarified. Also the real time tuning method of observer gain was proposed in [1]. The validity of the proposed method was confirmed on the simulation using Matlab Simulink and the experiment. Then this paper evaluates the experimental performance for low speed and regenerating operation of sensor-less vector control system of induction motor using observer gain tuning.

	Observer of Induction Motor Speed Based on Exact Disturbance Model By Zbigniew Krzemiński	[View] [Download]
Abstract: A simplified speed observer was proposed previously by the author to estimate the rotor speed needed in control system of a drive with induction motor. Small error of estimated rotor speed was observed but errors of the stator current and rotor flux vector components appear in dependence of rotor speed. A new structure of the speed observer is proposed now with exact disturbance model and gain coefficients depending on stator frequency. The new structure was derived from the previous one by analysis of dependencies appearing in differential equations. Explanation of observer stability is presented. Properties of the proposed observer are presented using simulations of full control system.

	State and Parameter Estimation in Induction Motors using Sliding Modes By Sachit Rao	[View] [Download]
Abstract: We present two observer based solutions to the popular problem of sensorless speed control of induction motors. The observers which provide simultaneous motor speed and flux estimation are based on the basic principles of sliding mode control theory. We present an observer, which incorporates rotor flux dynamics, that can also be used to simulataneously estimate rotor resistance (if unknown). We propose a second observer design, defined by stator flux dynamics, that is independent of the unknown rotor resistance. As for the controller of the induction motor itself, which now relies on the outputs of each observer, we propose designs again based on sliding mode control theory.

	Torque Sensorless Control of Induction Motor By Karel Jezernik	[View] [Download]
Abstract: In this paper the torque and speed sensorless induction motor (IM) control is presented. The main idea consists in utilizing the best qualities of the both nonlinear structures of the motor observer and the current controller. Motor observer is based on flux error between modeled and measured quantities. In addition, the rotor flux observer is using combination of the feedforward and feedback terms in order to enhance the sensitivity of the observer. Torque and stator current control as well as the rotor flux observer are based on the sliding mode theory, which results in high degree of robustness towards parameters variation and the external disturbances. Proposed control scheme is implemented on DSP system extended with FPGA where event-driven current controlled modulator is realized. DSP serves for time discrete speed control and observer, while time critical current control is implemented on FPGA. Results demonstrate high efficiency of the proposed estimation and control method.