EPE Association: EPE-PEMC 2002: Special Session: Non Linear Control of AC Drives and Speed Estimation

EPE-PEMC 2002: Special Session: Non Linear Control of AC Drives and Speed Estimation
You are here: EPE Documents > 04 - EPE-PEMC Conference Proceedings > EPE-PEMC 2002 - Conference > EPE-PEMC 2002: Special Session: Non Linear Control of AC Drives and Speed Estimation

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   Estimation of Rotor Speed for Nonlinear Control of the Induction Motor
By Z. Krzemiñski [View]
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Abstract: A nonlinear control system based on a multiscalar model of the induction motor is presented in the paper. Properties of the multiscalar model based system are compared with the field oriented control system. Structures of different rotor speed estimators suitable for nonlinear control are analyzed and their exactness in steady states and transients is presented. Special attention is paid to a speed observer proposed recently. The structure with estimation of rotor resistance and mutual inductance is presented. Results of simulations for investigated structures are presented. The most effective structure of nonlinear control system with speed estimation is pointed out. Properties of this system were investigated using a digital signal processor for realization of the control algorithm and results of experiments are presented.

   Robust Vector Control of Electrical Drives Using Load Torque Estimation: An FPGA Implemented Synchronous Motor Application
By S. J. Dodds; R. Perryman; S. Jayasoma [View]
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Abstract: A new control methodology for electrical drives is presented that offers high robustness to uncertainties in the dynamics of the driven load and unknown external load torques and yields a prescribed closed-loop dynamic response to reference inputs. The robustness is obtained using an observer which estimates the net load torque acting on the rotor of the motor that is equal to the sum of the external load torque and the dynamic load torque presented by the driven mechanical load. A control law is then formed that counteracts the real net load torque so that the closed-loop performance is virtually independent of the net load torque. A cascade control structure is employed in which the inner loop is a stator current control loop and the middle loop is a speed control loop yielding a first order dynamic response to a rotor speed reference input with prescribed settling time using the shaft speed estimate from the observer. This enables the drive to be used directly for speed control. If position control is required then an outer loop is closed around the speed control loop using the shaft encoder output. The gain of this loop and the settling time of the speed control loop are then set automatically to realise a second order closed-loop dynamic response to a shaft rotor position reference input having a settling time with either critical damping or a prescribed percentage overshoot. These features render the drive easily commissioned and used without the need for specialist expertise and also considerably aid the task of designing any control system in which the drive is embedded. Furthermore, existing vector controlled drives with digitally implemented controllers could be re-programmed to achieve the features presented here. The method is used to develop a synchronous motor based speed/position control system using a shaft encoder. The advance in the state-of-the-art inherent in the new control methodology is complemented by plans for a first-time implementation of the drive control system using FPGA technology to minimise the hardware complexity. The architecture of the system is fully explained. Simulation studies are presented, with emphasis on robustness and the effects of the encoder resolution at low or zero speeds during position control.

   Rotor Flux Observers and Speed Estimators for Sensorless Induction Motor Drives - Comparative Study
By T. Orlowska-Kowalska [View]
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Abstract: The paper deals with the comparison of different rotor flux and speed observers for sensorless vector control of the induction motor drive. The comparison of chosen flux and speed observers was per-formed in simulation – from the point of view of sensitivity to motor parameter changes, as well as in experiments - from the point of view of proper work in dynamical states and low speed region. The reduced and full order flux observer, with speed calculated based on estimated flux components and so called adaptive speed observer (MRAS) based on full order flux observer with adaptive speed loop were compared. The results of simulated and laboratory experiments, realised using the TMS320C31 digital signal processor are presented and the estimation quality is evaluated.

   Sensorless Induction Motor Drive With Vector Control
By P. Brandstetter; P. Palacky; D. Vinklarek; M. Kuchar [View]
[Download]

Abstract: Rotor position and speed sensors are required for vector control of induction motor. Because there are some applications in industry, where these sensors are not possible to use, sensormess control technique should be used. The paper deals with some different methods of estimators. At first, the open loop algorithms are described and then these methods are compared with another robust algorithm based on Kalman filter. Description of the control system with TMS320C40 DSP and practical results of proposed algorithms are given too.

   Shaft Sensorless Direct Vector Control of Induction Motor With Forced Dynamics
By M. Rapsík; J. Buday; J. Vittek [View]
[Download]

Abstract: An extension of direct vector control method for electric drives with induction motor to ‘Forced Dynamic Control’ is presented. This method offers accurate realisation of dynamic response characteristics, which can be selected by the user. The system operates without shaft sensors, only the stator currents being measured, the applied stator voltages being determined by the computed switching algorithm of inverter and with a knowledge of the dc link voltage. Obtained preliminary experimental results indicate good agreement with the theoretical predictions.

EPE-PEMC 2002: Special Session: Non Linear Control of AC Drives and Speed Estimation
You are here: EPE Documents > 04 - EPE-PEMC Conference Proceedings > EPE-PEMC 2002 - Conference > EPE-PEMC 2002: Special Session: Non Linear Control of AC Drives and Speed Estimation
	[return to parent folder]

	Estimation of Rotor Speed for Nonlinear Control of the Induction Motor By Z. Krzemiñski	[View] [Download]
Abstract: A nonlinear control system based on a multiscalar model of the induction motor is presented in the paper. Properties of the multiscalar model based system are compared with the field oriented control system. Structures of different rotor speed estimators suitable for nonlinear control are analyzed and their exactness in steady states and transients is presented. Special attention is paid to a speed observer proposed recently. The structure with estimation of rotor resistance and mutual inductance is presented. Results of simulations for investigated structures are presented. The most effective structure of nonlinear control system with speed estimation is pointed out. Properties of this system were investigated using a digital signal processor for realization of the control algorithm and results of experiments are presented.

	Robust Vector Control of Electrical Drives Using Load Torque Estimation: An FPGA Implemented Synchronous Motor Application By S. J. Dodds; R. Perryman; S. Jayasoma	[View] [Download]
Abstract: A new control methodology for electrical drives is presented that offers high robustness to uncertainties in the dynamics of the driven load and unknown external load torques and yields a prescribed closed-loop dynamic response to reference inputs. The robustness is obtained using an observer which estimates the net load torque acting on the rotor of the motor that is equal to the sum of the external load torque and the dynamic load torque presented by the driven mechanical load. A control law is then formed that counteracts the real net load torque so that the closed-loop performance is virtually independent of the net load torque. A cascade control structure is employed in which the inner loop is a stator current control loop and the middle loop is a speed control loop yielding a first order dynamic response to a rotor speed reference input with prescribed settling time using the shaft speed estimate from the observer. This enables the drive to be used directly for speed control. If position control is required then an outer loop is closed around the speed control loop using the shaft encoder output. The gain of this loop and the settling time of the speed control loop are then set automatically to realise a second order closed-loop dynamic response to a shaft rotor position reference input having a settling time with either critical damping or a prescribed percentage overshoot. These features render the drive easily commissioned and used without the need for specialist expertise and also considerably aid the task of designing any control system in which the drive is embedded. Furthermore, existing vector controlled drives with digitally implemented controllers could be re-programmed to achieve the features presented here. The method is used to develop a synchronous motor based speed/position control system using a shaft encoder. The advance in the state-of-the-art inherent in the new control methodology is complemented by plans for a first-time implementation of the drive control system using FPGA technology to minimise the hardware complexity. The architecture of the system is fully explained. Simulation studies are presented, with emphasis on robustness and the effects of the encoder resolution at low or zero speeds during position control.

	Rotor Flux Observers and Speed Estimators for Sensorless Induction Motor Drives - Comparative Study By T. Orlowska-Kowalska	[View] [Download]
Abstract: The paper deals with the comparison of different rotor flux and speed observers for sensorless vector control of the induction motor drive. The comparison of chosen flux and speed observers was per-formed in simulation – from the point of view of sensitivity to motor parameter changes, as well as in experiments - from the point of view of proper work in dynamical states and low speed region. The reduced and full order flux observer, with speed calculated based on estimated flux components and so called adaptive speed observer (MRAS) based on full order flux observer with adaptive speed loop were compared. The results of simulated and laboratory experiments, realised using the TMS320C31 digital signal processor are presented and the estimation quality is evaluated.

	Sensorless Induction Motor Drive With Vector Control By P. Brandstetter; P. Palacky; D. Vinklarek; M. Kuchar	[View] [Download]
Abstract: Rotor position and speed sensors are required for vector control of induction motor. Because there are some applications in industry, where these sensors are not possible to use, sensormess control technique should be used. The paper deals with some different methods of estimators. At first, the open loop algorithms are described and then these methods are compared with another robust algorithm based on Kalman filter. Description of the control system with TMS320C40 DSP and practical results of proposed algorithms are given too.

	Shaft Sensorless Direct Vector Control of Induction Motor With Forced Dynamics By M. Rapsík; J. Buday; J. Vittek	[View] [Download]
Abstract: An extension of direct vector control method for electric drives with induction motor to ‘Forced Dynamic Control’ is presented. This method offers accurate realisation of dynamic response characteristics, which can be selected by the user. The system operates without shaft sensors, only the stator currents being measured, the applied stator voltages being determined by the computed switching algorithm of inverter and with a knowledge of the dc link voltage. Obtained preliminary experimental results indicate good agreement with the theoretical predictions.