EPE Association: EPE 1985 - 13 - Lecture Session 2.06: CONTROL WITH SYNCHRONOUS MACHINES

EPE 1985 - 13 - Lecture Session 2.06: CONTROL WITH SYNCHRONOUS MACHINES
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   DRIVE SYSTEM CONTROL OF DOUBLE-FED INDUCTION MOTOR WORKING IN MOTOR AND GENERATOR MODE
By W. Koczara; J. Przybylski [View]
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Abstract: The paper describes a control scheme of a double-fed machine /DFM/, that is a drive system with a slip ring induction motor fed from the network side by voltage with a constant amplitude and frequency and controlled from the rotor side by changing the value, frequency and phase of the rotor voltage or current. Theoretical analysis regarding the characteristics structures and methods of control are presented. In the section refering to laboratory tests, the static and dynamic characteristics are presented. The paper ends with conclusions.

   EVALUATION OF CONVERTER HARMONlCS IN POWER SYSTEMS BY A DIRECT AND ANALYTICALLY BASED STATE VARIABLE APPROACH
By M. Grotzbach; R. Von Lutz [View]
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Abstract: The evaluation of harmonic distortions in electrical power systems leads to extensive parameter studies of periodically switched systems of high order. Usually these studies are carried out by means of rather general simulation programs. This may result in high computation times, especially for networks with a great difference in the time constants, and even in numerical problems. In this contribution a direct evaluation method for the steady state is presented, by which periodical harmonic distortions can be computed with lesser effort and moreover with greater accuracy. Starting from a piecewise description by state equations and from the continuity conditions of the state vector at the switching points, from the corresponding difference equation a first condition for the steady state is immediately obtained. Together with the switching equations a complete problem description in the form of non-linear equations results, which can be solved by an analytically based Newton-method. Apart from asymmetries in the net or in the converter even non-linear elements can be taken into account. For the practically most relevant case of a symmetrical operation, by taking advantage of the cyclical symmetry, an especially high reduction in the computation times follows.

   ANALYSIS OF DIFFERENT CURRENT CONTROL SYSTEMS FOR INVERTER-FED SYNCHRONOUS MACHINE
By C. Andrieux; M. Lajoie-Mazenc [View]
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Abstract: The paper reports the analysis of two typical systems used to control currents in a synchronous machine fed at variable speed by a transistorized inverter. These two systems (control by hysteresis and control by PWM) are briefly presented and compared by particularly using a numerical simulation of the complete device (machine + inverter + control). This comparative analysis concerns the operating principles, the constraints applied to inverter, the waveforms and some aspects of steady state and transient behaviour. Informations on determining the current loop regulator for the control by PWM are given and experimental results on a permanent magnet machine and a winding excited machine are shown.

   A SlMPLIFlED ANALYSlS OF THE RECTIFIER BRIDGE FED BY A POLYPHASE SYNCHRONOUS MACHINE
By M. Buyse; M. Compere; J. M. Thiry [View]
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Abstract: In the last years, the DC generator has been replaced, for many applications, by the association of a synchronous machine and a rectifier; the excitation of large turbo-alternators is one of these applications. This communication presents a simplified global model considering the rectifier-loaded synchronous generator as a DC machine with shifted brushes. The model can be used for synchronous machines having a number of phases larger than three or more than one armature circuit. For steady-state and transient conditions, the proposed method gives a good approximation of the average and instantaneous values of currents and voltages of the system and allows an accurate evaluation of the sollicitations of the semiconductor devices.

EPE 1985 - 13 - Lecture Session 2.06: CONTROL WITH SYNCHRONOUS MACHINES
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1985 - Conference > EPE 1985 - 13 - Lecture Session 2.06: CONTROL WITH SYNCHRONOUS MACHINES
	[return to parent folder]

	DRIVE SYSTEM CONTROL OF DOUBLE-FED INDUCTION MOTOR WORKING IN MOTOR AND GENERATOR MODE By W. Koczara; J. Przybylski	[View] [Download]
Abstract: The paper describes a control scheme of a double-fed machine /DFM/, that is a drive system with a slip ring induction motor fed from the network side by voltage with a constant amplitude and frequency and controlled from the rotor side by changing the value, frequency and phase of the rotor voltage or current. Theoretical analysis regarding the characteristics structures and methods of control are presented. In the section refering to laboratory tests, the static and dynamic characteristics are presented. The paper ends with conclusions.

	EVALUATION OF CONVERTER HARMONlCS IN POWER SYSTEMS BY A DIRECT AND ANALYTICALLY BASED STATE VARIABLE APPROACH By M. Grotzbach; R. Von Lutz	[View] [Download]
Abstract: The evaluation of harmonic distortions in electrical power systems leads to extensive parameter studies of periodically switched systems of high order. Usually these studies are carried out by means of rather general simulation programs. This may result in high computation times, especially for networks with a great difference in the time constants, and even in numerical problems. In this contribution a direct evaluation method for the steady state is presented, by which periodical harmonic distortions can be computed with lesser effort and moreover with greater accuracy. Starting from a piecewise description by state equations and from the continuity conditions of the state vector at the switching points, from the corresponding difference equation a first condition for the steady state is immediately obtained. Together with the switching equations a complete problem description in the form of non-linear equations results, which can be solved by an analytically based Newton-method. Apart from asymmetries in the net or in the converter even non-linear elements can be taken into account. For the practically most relevant case of a symmetrical operation, by taking advantage of the cyclical symmetry, an especially high reduction in the computation times follows.

	ANALYSIS OF DIFFERENT CURRENT CONTROL SYSTEMS FOR INVERTER-FED SYNCHRONOUS MACHINE By C. Andrieux; M. Lajoie-Mazenc	[View] [Download]
Abstract: The paper reports the analysis of two typical systems used to control currents in a synchronous machine fed at variable speed by a transistorized inverter. These two systems (control by hysteresis and control by PWM) are briefly presented and compared by particularly using a numerical simulation of the complete device (machine + inverter + control). This comparative analysis concerns the operating principles, the constraints applied to inverter, the waveforms and some aspects of steady state and transient behaviour. Informations on determining the current loop regulator for the control by PWM are given and experimental results on a permanent magnet machine and a winding excited machine are shown.

	A SlMPLIFlED ANALYSlS OF THE RECTIFIER BRIDGE FED BY A POLYPHASE SYNCHRONOUS MACHINE By M. Buyse; M. Compere; J. M. Thiry	[View] [Download]
Abstract: In the last years, the DC generator has been replaced, for many applications, by the association of a synchronous machine and a rectifier; the excitation of large turbo-alternators is one of these applications. This communication presents a simplified global model considering the rectifier-loaded synchronous generator as a DC machine with shifted brushes. The model can be used for synchronous machines having a number of phases larger than three or more than one armature circuit. For steady-state and transient conditions, the proposed method gives a good approximation of the average and instantaneous values of currents and voltages of the system and allows an accurate evaluation of the sollicitations of the semiconductor devices.