EPE Association: EPE 1987 - 15 - Lecture Session 2.1: SIGNAL PROCESSING (I)

EPE 1987 - 15 - Lecture Session 2.1: SIGNAL PROCESSING (I)
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   A Rotor Speed Detector for lnduction Machines Utilizing Rotor Slots Harmonics and an Active Three-Phase Injection
By B. Hämmerli; R. Tanner; R. Zwicky [View]
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Abstract: A new method to detect rotor speed electrically from rotor slots harmonics of a three-phase squirrel cage induction motor fed with a 20 kHz PWM inverter is presented. The rotor speed is detected in the range 20% to 100% of nominal speed directly by the rotor slots harmonics and in the range from 2% to 30% of nominal speed an additional 1 kHz three phase signal is fed from the inverter into the machine to produce an additional rotor-slot-rnodulation, which is used to detect rotor speed in this range. A comprehensive simulation of a model based on current distribution in the rotor and stator verifies the results of the realized drive. For the detector only a small amount of additional hardware is required.

   BINARY OBSERVERS IN ELECTRICAL DRIVES
By K. Hofer [View]
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Abstract: Sampling and processing of ripple values cause enormous problems in digital controlled converter-drives and make high requirements to anologous interfaces. A good and cheap software alternative is the implementation of Binary Observers, which calculate state variables dependent on binary converter informations such as firing delay, current flow time and overlap time. In contrast to classical converter drives the use of Binary Observers allows the realization of sensorless electrical drives for the first time. This paper deals with the mathematical description of Binary Observers. The observer functions for currents and voltages will be discussed in more detail using a dc-drive as an example. This new strategy can also be transformed to electrical drives fed by commutation-less or self-commutated converters. Furthermore periodical processes are given in some ranges of medicine, biology and physics so that the use of Binary Observers is manysided.

   A CONTACT FREE SYSTEM FOR THE MEASUREMENT OF ROTATION SPEED
By J. Durand; J. Lienard; C. Masselot [View]
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Abstract: Transit time of a drive shaft between two sensors is determined by cross correlation of the signals issued from the sensors. Depending of the response time, it is possible to measure the period of rotation by using only one sensor. A specialized micro computer including the correlator has been developped which calculates directly the speed of the drive shaft from the signals, thus performing contact-free speed measurement.

   HIGH-SPEED COMMUNICATIONS VIA SERIAL AND PARALLEL INTERFACES IN DRIVE ENGINEERING
By Ingo Hackel [View]
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Abstract: High-speed communications in automation and in links between variabie-speed drives confronts all the elements of communications with extreme problems. Because of the constraints placed on the baud rates of economically viable interface hardware and the program processing times required in cascaded microcomputers, considerable transport deadtimes result if software processing is not properly timed. In the case of short messages, the bus procedures have a considerable influence on the time required to transmit messages. The message contents can be kept short by omitting addresses for declared string locations in messages, and by using fixed-point notation and binary coding for words and addresses in numerical representation. User-configured communication data fields permit the use of relatively simple and short message contents even in system environments. Random data access via cascaded LANs and cascaded processor functions in systems with symbolic addresses can only be handled by special communications methods. The emerging standardization of low-costs LANs and serial interface, including LANs for drives, must take the special conditions prevailing for drive technology into account.

EPE 1987 - 15 - Lecture Session 2.1: SIGNAL PROCESSING (I)
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1987 - Conference > EPE 1987 - 15 - Lecture Session 2.1: SIGNAL PROCESSING (I)
	[return to parent folder]

	A Rotor Speed Detector for lnduction Machines Utilizing Rotor Slots Harmonics and an Active Three-Phase Injection By B. Hämmerli; R. Tanner; R. Zwicky	[View] [Download]
Abstract: A new method to detect rotor speed electrically from rotor slots harmonics of a three-phase squirrel cage induction motor fed with a 20 kHz PWM inverter is presented. The rotor speed is detected in the range 20% to 100% of nominal speed directly by the rotor slots harmonics and in the range from 2% to 30% of nominal speed an additional 1 kHz three phase signal is fed from the inverter into the machine to produce an additional rotor-slot-rnodulation, which is used to detect rotor speed in this range. A comprehensive simulation of a model based on current distribution in the rotor and stator verifies the results of the realized drive. For the detector only a small amount of additional hardware is required.

	BINARY OBSERVERS IN ELECTRICAL DRIVES By K. Hofer	[View] [Download]
Abstract: Sampling and processing of ripple values cause enormous problems in digital controlled converter-drives and make high requirements to anologous interfaces. A good and cheap software alternative is the implementation of Binary Observers, which calculate state variables dependent on binary converter informations such as firing delay, current flow time and overlap time. In contrast to classical converter drives the use of Binary Observers allows the realization of sensorless electrical drives for the first time. This paper deals with the mathematical description of Binary Observers. The observer functions for currents and voltages will be discussed in more detail using a dc-drive as an example. This new strategy can also be transformed to electrical drives fed by commutation-less or self-commutated converters. Furthermore periodical processes are given in some ranges of medicine, biology and physics so that the use of Binary Observers is manysided.

	A CONTACT FREE SYSTEM FOR THE MEASUREMENT OF ROTATION SPEED By J. Durand; J. Lienard; C. Masselot	[View] [Download]
Abstract: Transit time of a drive shaft between two sensors is determined by cross correlation of the signals issued from the sensors. Depending of the response time, it is possible to measure the period of rotation by using only one sensor. A specialized micro computer including the correlator has been developped which calculates directly the speed of the drive shaft from the signals, thus performing contact-free speed measurement.

	HIGH-SPEED COMMUNICATIONS VIA SERIAL AND PARALLEL INTERFACES IN DRIVE ENGINEERING By Ingo Hackel	[View] [Download]
Abstract: High-speed communications in automation and in links between variabie-speed drives confronts all the elements of communications with extreme problems. Because of the constraints placed on the baud rates of economically viable interface hardware and the program processing times required in cascaded microcomputers, considerable transport deadtimes result if software processing is not properly timed. In the case of short messages, the bus procedures have a considerable influence on the time required to transmit messages. The message contents can be kept short by omitting addresses for declared string locations in messages, and by using fixed-point notation and binary coding for words and addresses in numerical representation. User-configured communication data fields permit the use of relatively simple and short message contents even in system environments. Random data access via cascaded LANs and cascaded processor functions in systems with symbolic addresses can only be handled by special communications methods. The emerging standardization of low-costs LANs and serial interface, including LANs for drives, must take the special conditions prevailing for drive technology into account.