EPE Association: EPE 1985 - 36 - Late Papers 1.1: LATE PAPERS

EPE 1985 - 36 - Late Papers 1.1: LATE PAPERS
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1985 - Conference > EPE 1985 - 36 - Late Papers 1.1: LATE PAPERS

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   COORDINATED VOLTAGE FREQUENCY CONTROL IN INDUCTION MOTOR FED BY VARIABLE FREQUENCY SUPPLIES
By J. Chen [View]
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Abstract: For squirrel cage motors fed by variable voltage and variable frequency static converters, the Voltage V1 and frequency W1 can be independently adjusted. This makes the adjustment of the speed and the control of torque simple and flexible. As long as controlling the ratio of V1 / W1 the drive system can operate in the optimization of the performance or economic optimization. As the frequency W1 is greater than the rated frequency W1r, for which the motor has been designed, the induction motor should operate in corresponding "field weakening" range of operation with the rated value Vir. As the frequency W1 is less than the rated frequency W1r, the stator voltage V1 should decrease correspondingly, but the flux can be held with the brated value. Therefore drive system's maximum power should also decrease. The maximum torque can be held with the rated value. Then the drive system can only obtain a constant maximum torque characteristic. In the case of W1 < W1r, how to control and adjust the ratio V1 / W1, depends on the requirement of the drive performance and operation economics, and also on whether it is flexible and simple or not. This paper describes varied basic principles for controlling the ratio V1 / W1 to improve the speed-torque characteristics. These control principles for induction motors in variable frequency operation are:
1. Keep the ratio V1 / W1 constant
2. Keep the stator flux linkage constant
3. Keep the air-gap flux linkage constant
4. Keep the rotor flux linkage constant
5. Keep the maximum torque in variable-frequency operation equal to the maximum torque in the rated frequency and rated voltage operation.

   MICROCOMPUTER BASED CONTROLLER FOR A CURRENT SOURCE INVERTER FED SYNCHRONOUS MOTOR DRIVE
By Alok Saxena; Adel M. Sharaf [View]
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Abstract: This paper presents microcomputer implementation of a robust optimal controller for current source inverter fed synchronous motor drive. The paper also includes modelling of the drive system, design of control strategy and digital simulation of the drive system with quadratic optimal controller. The controller is implemented on a microcomputer system and tested on a synchronous motor drive system in the laboratory.

   STRESSES ON SVC VALVES AND PROTECTIONS
By P. Charles [View]
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Abstract: This paper deals with thyristor valves used for SVC on Transmission Networks. Each Static Switch is made of several series connected thyristor levels, which number is proportional to the required voltage withstand. This voltage value depends on transient stresses. In order to satisfy more and more severe operation conditions, a special protection design has been built up. This results in improved reliability and dynamic behaviour, less thyristor levels put in series and lower electrical losses. After a short description of SVC system and valve design, will be introduced steady-state stresses on Thyristor Control Reactors (TCR) or Thyristor Switched Reactors (TSC) and then on Thyristor Switched Capacitor (TSC). Next will be described the protective system design and transient stresses in relation with this protection operation. Some emphasis will be made about HV line switchings on weak systems or networks, for which a SVC can be a conclusive solution.

   A POWER HYBRID TECHNOLOGY SPECIALLY DESIGNED FOR MILITARY AND CIVIL APPLICATIONS
By Didier Quillot [View]
[Download]

Abstract: For THOMSON HYBRID IC's, the development of a "Power Hybrid" die has become a major axis of development. This new branch has provided a complementary solution for the range of available techniques for miniaturisation of electronic equipment. Many manufacturers have found it necessary to reduce the volume of power stages for electronic systems. These stages exist in all types of equipment, forming a type of "Energy processing chain". Their role is energy commutation from source to commutation units. Over many years, there has been a tenfold increase in performance for power components and associated circuits (control, amplifier, interface, etc...), which have become preciser and more complex. In this field, attempts at miniaturisation are highly limited by mechanical and thermal constraints (casings, cooling, insultation, etc...) and the wide range of uses. Today, THOMSON Power Hybrids enable coexistence of both power semiconductors and associated electronics, insulated from one another within a single casing. The range extends from 1 to 10 A, or up to 60 W. Where the main aim is miniaturisation, the advantages gained from the power hybrid extend beyond hybrid electronics, as mechanical and thermal design of the equipment is facilitated.

   FERRITE CORES AND MATERIALS FOR SWITCHED MODE POWER SUPPLIES
By P. Beuzelin; P. Gaudry [View]
[Download]

Abstract: In switched mode power supplies, wound ferrite cores fulfill important functions such as output transformers, smoothing chokes and noise suppression filters which permit to afford regulated output power from different sources, even noisy ones, and also to gain on efficiency, weight, volume and cost of the converters. Depending on its type, its throughput power and the frequency at which it operates, different materials in different core shapes are needed. After summarizing the main types of cores, the main characteristics and the trends in materials are given.

EPE 1985 - 36 - Late Papers 1.1: LATE PAPERS
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1985 - Conference > EPE 1985 - 36 - Late Papers 1.1: LATE PAPERS
	[return to parent folder]

	COORDINATED VOLTAGE FREQUENCY CONTROL IN INDUCTION MOTOR FED BY VARIABLE FREQUENCY SUPPLIES By J. Chen	[View] [Download]
Abstract: For squirrel cage motors fed by variable voltage and variable frequency static converters, the Voltage V1 and frequency W1 can be independently adjusted. This makes the adjustment of the speed and the control of torque simple and flexible. As long as controlling the ratio of V1 / W1 the drive system can operate in the optimization of the performance or economic optimization. As the frequency W1 is greater than the rated frequency W1r, for which the motor has been designed, the induction motor should operate in corresponding "field weakening" range of operation with the rated value Vir. As the frequency W1 is less than the rated frequency W1r, the stator voltage V1 should decrease correspondingly, but the flux can be held with the brated value. Therefore drive system's maximum power should also decrease. The maximum torque can be held with the rated value. Then the drive system can only obtain a constant maximum torque characteristic. In the case of W1 < W1r, how to control and adjust the ratio V1 / W1, depends on the requirement of the drive performance and operation economics, and also on whether it is flexible and simple or not. This paper describes varied basic principles for controlling the ratio V1 / W1 to improve the speed-torque characteristics. These control principles for induction motors in variable frequency operation are: 1. Keep the ratio V1 / W1 constant 2. Keep the stator flux linkage constant 3. Keep the air-gap flux linkage constant 4. Keep the rotor flux linkage constant 5. Keep the maximum torque in variable-frequency operation equal to the maximum torque in the rated frequency and rated voltage operation.

	MICROCOMPUTER BASED CONTROLLER FOR A CURRENT SOURCE INVERTER FED SYNCHRONOUS MOTOR DRIVE By Alok Saxena; Adel M. Sharaf	[View] [Download]
Abstract: This paper presents microcomputer implementation of a robust optimal controller for current source inverter fed synchronous motor drive. The paper also includes modelling of the drive system, design of control strategy and digital simulation of the drive system with quadratic optimal controller. The controller is implemented on a microcomputer system and tested on a synchronous motor drive system in the laboratory.

	STRESSES ON SVC VALVES AND PROTECTIONS By P. Charles	[View] [Download]
Abstract: This paper deals with thyristor valves used for SVC on Transmission Networks. Each Static Switch is made of several series connected thyristor levels, which number is proportional to the required voltage withstand. This voltage value depends on transient stresses. In order to satisfy more and more severe operation conditions, a special protection design has been built up. This results in improved reliability and dynamic behaviour, less thyristor levels put in series and lower electrical losses. After a short description of SVC system and valve design, will be introduced steady-state stresses on Thyristor Control Reactors (TCR) or Thyristor Switched Reactors (TSC) and then on Thyristor Switched Capacitor (TSC). Next will be described the protective system design and transient stresses in relation with this protection operation. Some emphasis will be made about HV line switchings on weak systems or networks, for which a SVC can be a conclusive solution.

	A POWER HYBRID TECHNOLOGY SPECIALLY DESIGNED FOR MILITARY AND CIVIL APPLICATIONS By Didier Quillot	[View] [Download]
Abstract: For THOMSON HYBRID IC's, the development of a "Power Hybrid" die has become a major axis of development. This new branch has provided a complementary solution for the range of available techniques for miniaturisation of electronic equipment. Many manufacturers have found it necessary to reduce the volume of power stages for electronic systems. These stages exist in all types of equipment, forming a type of "Energy processing chain". Their role is energy commutation from source to commutation units. Over many years, there has been a tenfold increase in performance for power components and associated circuits (control, amplifier, interface, etc...), which have become preciser and more complex. In this field, attempts at miniaturisation are highly limited by mechanical and thermal constraints (casings, cooling, insultation, etc...) and the wide range of uses. Today, THOMSON Power Hybrids enable coexistence of both power semiconductors and associated electronics, insulated from one another within a single casing. The range extends from 1 to 10 A, or up to 60 W. Where the main aim is miniaturisation, the advantages gained from the power hybrid extend beyond hybrid electronics, as mechanical and thermal design of the equipment is facilitated.

	FERRITE CORES AND MATERIALS FOR SWITCHED MODE POWER SUPPLIES By P. Beuzelin; P. Gaudry	[View] [Download]
Abstract: In switched mode power supplies, wound ferrite cores fulfill important functions such as output transformers, smoothing chokes and noise suppression filters which permit to afford regulated output power from different sources, even noisy ones, and also to gain on efficiency, weight, volume and cost of the converters. Depending on its type, its throughput power and the frequency at which it operates, different materials in different core shapes are needed. After summarizing the main types of cores, the main characteristics and the trends in materials are given.