EPE Association: EPE 1989 - 20 - Lecture Session 3.3: ELECTRONIC POWER ACTUATORS

EPE 1989 - 20 - Lecture Session 3.3: ELECTRONIC POWER ACTUATORS
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1989 - Conference > EPE 1989 - 20 - Lecture Session 3.3: ELECTRONIC POWER ACTUATORS

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   NEW RECTIFIER CIRCUITS WITH LOW MAINS POLLUTION AND ADDITIONAL LOW COST INVERTER FOR ENERGY RECOVERY
By Clemens Niermann [View]
[Download]

Abstract: For three-phase rectification two new rectifier circuits with 12-pulse or 18-pulse characteristic and constant DC-voltage output are presented. These circuits avoid unwanted harmonics especially of order 5 and 7. To get the desired 12-pulse or 18-pulse performance two new Line-side Interphase Transformer (LIT) connections without isolation are developed . These circuits are characterized by nearly sinusoidal line currents and low costs. At nominal conditions the distortion content of the line currents is less than 7% and the power factor is better than 0.97. The circuits only consist of line-commutated, three-phase diode rectifier bridges and few moderate sized magnetic components. If energy recovery is wanted a 6-pulse, line-commutated thyristor inverter bridge can be added to the rectifier circuits. This inverter needs no additional reactors and no transformer for isolation or voltage adaption.

   IMPROVEMENT IN VOLTAGE SAGS IMMUNITY WITH A NEW FIRING CONCEPT OF CONVERTERS
By R. Chekili; J. Maire; J. P. Louis [View]
[Download]

Abstract: The report considers the problems due to voltage sags and short outages which affect the operation of the line commutated converters. The today existing possibilities to remedy those difficulties do not solve really the problem, in particular for what concerns the keeping of converter characteristics in case of disturbances on the supply network. A new control strategy, which corresponds to a simple and original conception of the firing function allows a significant improvement of the presently existing devices . This monitoring strategy has been confirmed by numerical simulations and by experimerts in the case of a variable speed drive for a direct current motor.

   SYNTHESIS OF CYCLOCONVERTER AND CURRENT-SOURCE-INVERTER FOR HIGH POWER HIGH PERFORMANCE DRIVES
By P. Hussels; M. Mehne [View]
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Abstract: Cycloconverters and current-source-inverters both have proved performance for drives in the MW-range. They operate best in combination with a synchronous motor. The cycloconverter drive has very low torque ripple from zero start-up until a relatively small frequency, while the current-source-inverter causes high torque ripple disturbing only at low frequencies and it's maximum frequency is much higher than that of the cycloconverter . This paper describes the synthesis of both systems. The same circuit operates as a cycloconverter at start-up and low speeds of the motor, corresponding to low frequencies, and as a current-source-inverter at high speeds. Special attention is paid to the switch over between the two different modes of operation. First experiments show successfull switch over from one operating mode to the other.

   A METHODOLOGY FOR THE AUTOMATIC GENERATION OF MODELS IN THE ANALYSIS OF STATIC POWER CONVERSION SYSTEMS
By A. Bellini; C. Picardi [View]
[Download]

Abstract: The paper fits in the researches aiming at the development of techniques for the analysis of the behaviour of the electrical or electromechanical systems including static converters and presents a methodology for the automatic generation of the models which characterize the system in the different circuit configurations. The methodology defines an initial model of the system which is independent of the conducting state of the power semiconductors. Successively such a model is adapted to the different circuit configurations by a suitable sequence of modifications depending on the connections realized by the power semiconductors among the elementary components of the system.

   POWER INVERTER WITH SELF-TUNING OUTPUT FREQUENCY FOR ULTRASONIC CLEANING SYSTEM
By P. Fabijanski; L. Palczynski [View]
[Download]

Abstract: In this paper is presented the control method of the high-frequency generator for supply piezoelectric transducers used in ultrasonic cleaning systems. This method makes it possible to obtain the maximum cleaning efficiency by variable resonant frequency of the transducers. The operation of the high-frequency inverter is analysed with an R-C load model of the piezoelectric transducer. A power generator with the new control method was built and tested.

EPE 1989 - 20 - Lecture Session 3.3: ELECTRONIC POWER ACTUATORS
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1989 - Conference > EPE 1989 - 20 - Lecture Session 3.3: ELECTRONIC POWER ACTUATORS
	[return to parent folder]

	NEW RECTIFIER CIRCUITS WITH LOW MAINS POLLUTION AND ADDITIONAL LOW COST INVERTER FOR ENERGY RECOVERY By Clemens Niermann	[View] [Download]
Abstract: For three-phase rectification two new rectifier circuits with 12-pulse or 18-pulse characteristic and constant DC-voltage output are presented. These circuits avoid unwanted harmonics especially of order 5 and 7. To get the desired 12-pulse or 18-pulse performance two new Line-side Interphase Transformer (LIT) connections without isolation are developed . These circuits are characterized by nearly sinusoidal line currents and low costs. At nominal conditions the distortion content of the line currents is less than 7% and the power factor is better than 0.97. The circuits only consist of line-commutated, three-phase diode rectifier bridges and few moderate sized magnetic components. If energy recovery is wanted a 6-pulse, line-commutated thyristor inverter bridge can be added to the rectifier circuits. This inverter needs no additional reactors and no transformer for isolation or voltage adaption.

	IMPROVEMENT IN VOLTAGE SAGS IMMUNITY WITH A NEW FIRING CONCEPT OF CONVERTERS By R. Chekili; J. Maire; J. P. Louis	[View] [Download]
Abstract: The report considers the problems due to voltage sags and short outages which affect the operation of the line commutated converters. The today existing possibilities to remedy those difficulties do not solve really the problem, in particular for what concerns the keeping of converter characteristics in case of disturbances on the supply network. A new control strategy, which corresponds to a simple and original conception of the firing function allows a significant improvement of the presently existing devices . This monitoring strategy has been confirmed by numerical simulations and by experimerts in the case of a variable speed drive for a direct current motor.

	SYNTHESIS OF CYCLOCONVERTER AND CURRENT-SOURCE-INVERTER FOR HIGH POWER HIGH PERFORMANCE DRIVES By P. Hussels; M. Mehne	[View] [Download]
Abstract: Cycloconverters and current-source-inverters both have proved performance for drives in the MW-range. They operate best in combination with a synchronous motor. The cycloconverter drive has very low torque ripple from zero start-up until a relatively small frequency, while the current-source-inverter causes high torque ripple disturbing only at low frequencies and it's maximum frequency is much higher than that of the cycloconverter . This paper describes the synthesis of both systems. The same circuit operates as a cycloconverter at start-up and low speeds of the motor, corresponding to low frequencies, and as a current-source-inverter at high speeds. Special attention is paid to the switch over between the two different modes of operation. First experiments show successfull switch over from one operating mode to the other.

	A METHODOLOGY FOR THE AUTOMATIC GENERATION OF MODELS IN THE ANALYSIS OF STATIC POWER CONVERSION SYSTEMS By A. Bellini; C. Picardi	[View] [Download]
Abstract: The paper fits in the researches aiming at the development of techniques for the analysis of the behaviour of the electrical or electromechanical systems including static converters and presents a methodology for the automatic generation of the models which characterize the system in the different circuit configurations. The methodology defines an initial model of the system which is independent of the conducting state of the power semiconductors. Successively such a model is adapted to the different circuit configurations by a suitable sequence of modifications depending on the connections realized by the power semiconductors among the elementary components of the system.

	POWER INVERTER WITH SELF-TUNING OUTPUT FREQUENCY FOR ULTRASONIC CLEANING SYSTEM By P. Fabijanski; L. Palczynski	[View] [Download]
Abstract: In this paper is presented the control method of the high-frequency generator for supply piezoelectric transducers used in ultrasonic cleaning systems. This method makes it possible to obtain the maximum cleaning efficiency by variable resonant frequency of the transducers. The operation of the high-frequency inverter is analysed with an R-C load model of the piezoelectric transducer. A power generator with the new control method was built and tested.