EPE Association: EPE 1995 - 06 - Lecture Session L2b: CONTROL (I)

EPE 1995 - 06 - Lecture Session L2b: CONTROL (I)
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1995 - Conference > EPE 1995 - 06 - Lecture Session L2b: CONTROL (I)

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   STATE-ORIENTED CONTROL OF OPTIMIZED PULSE PATTERNS APPLIED TO A PWM CURRENT SOURCE INVERTER
By R. Vogel [View]
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Abstract: A novel modulation strategy for high power inverters operating at low switching frequencies is discribed. It combines the advantages of offline optimized pulse patterns in steady state operation with the fast dynamic response of a state-oriented control that operates in real-time. The new strategy was developed specifically for the line side of PWM current source AC to AC converters, but it can be applied to the machine side or to PWM voltage source inverters as well.

   Multivariable Robust control of a synchronous servomotor associated to a PWM inverter
By Y. Bonnassieux; M. Fadli; B. Le Pioufle; F. Aioun [View]
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Abstract: This paper presents a performing, robust multivariable current controller of a synchronous servomotor associated to a PWM inverter. The purpose of this paper is a constant parameters controller which stabilizes the system, despite high variations of the system parameters, low sampling frequency and low PWM switching frequency. The authors show that all constraints of robustness can be introduced in a generalized plant by using frequencyweighting transfer functions. Simulation and experimental results on a DSP96000 are discussed and demonstrate the effectiveness of the proposed method.

   ROTOR TIME CONSTANT IDENTIFICATION IN SENSORLESS VECTOR CONTROL DRIVES USING ROTOR SLOT HARMONICS
By R. Blasco-Gimenez; G. M. Asher; M. Sumner [View]
[Download]

Abstract: This paper describes the methodologies by which real time speed measurement obtained from the spectral estimation of rotor slot harmonics present in the stator currents of a cage induction machine are employed to identify the value of the rotor time constant. An alldigital method, based on the Fast Fourier Transform (FFT), is employed to obtain a real-time speed measurement with very high accuracy and robustness. This speed measurement is then used to tune a model-reference closed-loop flux and speed estimator against rotor time constant variation. Although the accuracy of the rotor time constant estimate is dependant on the accuracy of the rest of the machine parameters, the speed estimate from the model-reference speed estimator follows the actual speed of the machine very accurately. The speed holding capability of the resulting sensorless vector control drive is therefore increased.

   ROBUST SPEED AND PARAMETER ESTIMATION IN INDUCTION MOTORS
By H. Borsting; P. Vadstrup [View]
[Download]

Abstract: This paper presents a Model Reference Adaptive System (MRAS) for the estimation of the induction motor speed, based on measured terminal voltages and currents. In order to make the speed estimate insensitive to variation in rotor resistance, the method is combined with an on-line parameter estimation. Robustness against instability caused by insufficient information content in the measured signals is obtained using a selective forgetting method. Experimental results show that the estimation of the rotor speed and resistance using a selective forgetting method is a promising approach for accurate speed estimation. All results in this paper are based on experiments carried out on a laboratory setup.

EPE 1995 - 06 - Lecture Session L2b: CONTROL (I)
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1995 - Conference > EPE 1995 - 06 - Lecture Session L2b: CONTROL (I)
	[return to parent folder]

	STATE-ORIENTED CONTROL OF OPTIMIZED PULSE PATTERNS APPLIED TO A PWM CURRENT SOURCE INVERTER By R. Vogel	[View] [Download]
Abstract: A novel modulation strategy for high power inverters operating at low switching frequencies is discribed. It combines the advantages of offline optimized pulse patterns in steady state operation with the fast dynamic response of a state-oriented control that operates in real-time. The new strategy was developed specifically for the line side of PWM current source AC to AC converters, but it can be applied to the machine side or to PWM voltage source inverters as well.

	Multivariable Robust control of a synchronous servomotor associated to a PWM inverter By Y. Bonnassieux; M. Fadli; B. Le Pioufle; F. Aioun	[View] [Download]
Abstract: This paper presents a performing, robust multivariable current controller of a synchronous servomotor associated to a PWM inverter. The purpose of this paper is a constant parameters controller which stabilizes the system, despite high variations of the system parameters, low sampling frequency and low PWM switching frequency. The authors show that all constraints of robustness can be introduced in a generalized plant by using frequencyweighting transfer functions. Simulation and experimental results on a DSP96000 are discussed and demonstrate the effectiveness of the proposed method.

	ROTOR TIME CONSTANT IDENTIFICATION IN SENSORLESS VECTOR CONTROL DRIVES USING ROTOR SLOT HARMONICS By R. Blasco-Gimenez; G. M. Asher; M. Sumner	[View] [Download]
Abstract: This paper describes the methodologies by which real time speed measurement obtained from the spectral estimation of rotor slot harmonics present in the stator currents of a cage induction machine are employed to identify the value of the rotor time constant. An alldigital method, based on the Fast Fourier Transform (FFT), is employed to obtain a real-time speed measurement with very high accuracy and robustness. This speed measurement is then used to tune a model-reference closed-loop flux and speed estimator against rotor time constant variation. Although the accuracy of the rotor time constant estimate is dependant on the accuracy of the rest of the machine parameters, the speed estimate from the model-reference speed estimator follows the actual speed of the machine very accurately. The speed holding capability of the resulting sensorless vector control drive is therefore increased.

	ROBUST SPEED AND PARAMETER ESTIMATION IN INDUCTION MOTORS By H. Borsting; P. Vadstrup	[View] [Download]
Abstract: This paper presents a Model Reference Adaptive System (MRAS) for the estimation of the induction motor speed, based on measured terminal voltages and currents. In order to make the speed estimate insensitive to variation in rotor resistance, the method is combined with an on-line parameter estimation. Robustness against instability caused by insufficient information content in the measured signals is obtained using a selective forgetting method. Experimental results show that the estimation of the rotor speed and resistance using a selective forgetting method is a promising approach for accurate speed estimation. All results in this paper are based on experiments carried out on a laboratory setup.