EPE Association: EPE 1985 - 12 - Lecture Session 2.05: SIMULATION AND CAD

EPE 1985 - 12 - Lecture Session 2.05: SIMULATION AND CAD
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   AUTOMATIC DESIGN OF MICROPROCESSOR CONTROL CIRCUITS FOR STATIC POWER CONVERTERS
By J. Peire; F. Yeves; J. G. Aleixandre; F. Aldana [View]
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Abstract: This paper presents a new method for design of microprocessor control circuits for static power converters with the aided of computer. The system user chooses one static power converter among the different ones that the developed program offers. Automatically this program, working with several data files, loads a EPROM for its direct use in the control circuit, governed by microprocessor. This method is based on the development of both the so called "control rose theory" and the "existential function modulation". Several prototypes have been built and tested.

   PROBABILISTIC STUDY OF FAILURES IN CONVERTERS
By F. Sellami; F. Bordry [View]
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Abstract: In this paper, the authors present a method to evaluate the sensitivity of thyristor converters to parasites. The parasitic impulses are considered as random perturbations. The evolution which these impulses give to a system can cause significant consequences. It is therefore necessary to develop mathematical models to study the system's behaviour with respect to these disturbances. The evaluation of the probability of correct functionning is also absolutely essential. In the proposed study, the control signals as well as the parasitic signals are represented in vector from which a theoretical development technique is deduced. This technique allows the determination of the probability of correct functionning of an m thyristor system subjected to n parasitic impulses in an operation cycle. The method is subsequently applied to two autoadaptative choppers. This study gives the best choice of system structure and control strategy for a safe operation.

   A DIGITAL COMPUTER MODEL OF THREE-PHASE RECTIFIER / INVERTER SYSTEMS FOR TRANSIENT STUDIES
By R. J. Harrington; S. A. Gawish [View]
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Abstract: The waveform and transient response of a three-phase rectifier bridge, a three-phase forced commutated inverter and a three-phase naturally-commutated inverter were simulated on a digital computer from basic circuit theory. The "real" characteristics of the thryristors were also simulated. The simulations were further modified to allow for three-phase currents with adjustable frequency to be used for adjustable speed drives or start-up of synchronous motors. The interaction between the load and the inverter circuit was investigated during the normal operation of the naturally-commutated inverter. The operations of that inverter during faults occurring both on the line and in the inverter circuit were also investigated. These faults included three-phase short circuit, line-to-line faults and thyristor failure. Each of the three FORTRAN developed computer programs has three subprograms. The first contains the logic concerned with the operation of six thyristors (and diodes) of the bridge. Depending upon which thyristors (and diodes) are conducting, the second subprogram determines the corresponding differential equations which will be solved in the third subprogram.

   SIMULATION OF MICROCOMPUTER CONTROL OF DC THYRISTOR CHOPPERS FOR TRACTION VEHICLE
By K. Karwowski [View]
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Abstract: The papers deals with a multi-function microcomputer based controller used in rail-vehicles. The analysis has been presented, of how to use a microprocessor to control a thyristor chopper drive on these vehicles. Using concepts of a theory for discrete-dynamical systems, a mathematical model has been proposed for the vehicle with the microprocessor controls. Introduction of algebraic system concepts made feasible a decomposition of a system under study, which simplified the simulation program structure. The correctness of the simulation model, control algorithms and parameters of the controller have been verified by means of a digital computer. Some computation results have been presented for a start-up of the vehicle.

   SIMULATION OF POWER-ELECTRONIC SYSTEMS - COMPUTATIONAL METHOD USING VARIABLE STEP
By F. Bordry; D. Martins [View]
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Abstract: This paper presents a method for simulating switch-functioning semiconductor electric circuits. The method only requires knowledge of the circuit structure, its parameters and the control order of the semiconductors being controlled. Particular attention has been paid to the modelling of the semiconductors and particularly to the computation method. In the simulation program, the calculation step is variable, this is determined based on the time constants of the device. This original method allows to obtain a very high accuracy by in addition a short calculation time.

EPE 1985 - 12 - Lecture Session 2.05: SIMULATION AND CAD
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1985 - Conference > EPE 1985 - 12 - Lecture Session 2.05: SIMULATION AND CAD
	[return to parent folder]

	AUTOMATIC DESIGN OF MICROPROCESSOR CONTROL CIRCUITS FOR STATIC POWER CONVERTERS By J. Peire; F. Yeves; J. G. Aleixandre; F. Aldana	[View] [Download]
Abstract: This paper presents a new method for design of microprocessor control circuits for static power converters with the aided of computer. The system user chooses one static power converter among the different ones that the developed program offers. Automatically this program, working with several data files, loads a EPROM for its direct use in the control circuit, governed by microprocessor. This method is based on the development of both the so called "control rose theory" and the "existential function modulation". Several prototypes have been built and tested.

	PROBABILISTIC STUDY OF FAILURES IN CONVERTERS By F. Sellami; F. Bordry	[View] [Download]
Abstract: In this paper, the authors present a method to evaluate the sensitivity of thyristor converters to parasites. The parasitic impulses are considered as random perturbations. The evolution which these impulses give to a system can cause significant consequences. It is therefore necessary to develop mathematical models to study the system's behaviour with respect to these disturbances. The evaluation of the probability of correct functionning is also absolutely essential. In the proposed study, the control signals as well as the parasitic signals are represented in vector from which a theoretical development technique is deduced. This technique allows the determination of the probability of correct functionning of an m thyristor system subjected to n parasitic impulses in an operation cycle. The method is subsequently applied to two autoadaptative choppers. This study gives the best choice of system structure and control strategy for a safe operation.

	A DIGITAL COMPUTER MODEL OF THREE-PHASE RECTIFIER / INVERTER SYSTEMS FOR TRANSIENT STUDIES By R. J. Harrington; S. A. Gawish	[View] [Download]
Abstract: The waveform and transient response of a three-phase rectifier bridge, a three-phase forced commutated inverter and a three-phase naturally-commutated inverter were simulated on a digital computer from basic circuit theory. The "real" characteristics of the thryristors were also simulated. The simulations were further modified to allow for three-phase currents with adjustable frequency to be used for adjustable speed drives or start-up of synchronous motors. The interaction between the load and the inverter circuit was investigated during the normal operation of the naturally-commutated inverter. The operations of that inverter during faults occurring both on the line and in the inverter circuit were also investigated. These faults included three-phase short circuit, line-to-line faults and thyristor failure. Each of the three FORTRAN developed computer programs has three subprograms. The first contains the logic concerned with the operation of six thyristors (and diodes) of the bridge. Depending upon which thyristors (and diodes) are conducting, the second subprogram determines the corresponding differential equations which will be solved in the third subprogram.

	SIMULATION OF MICROCOMPUTER CONTROL OF DC THYRISTOR CHOPPERS FOR TRACTION VEHICLE By K. Karwowski	[View] [Download]
Abstract: The papers deals with a multi-function microcomputer based controller used in rail-vehicles. The analysis has been presented, of how to use a microprocessor to control a thyristor chopper drive on these vehicles. Using concepts of a theory for discrete-dynamical systems, a mathematical model has been proposed for the vehicle with the microprocessor controls. Introduction of algebraic system concepts made feasible a decomposition of a system under study, which simplified the simulation program structure. The correctness of the simulation model, control algorithms and parameters of the controller have been verified by means of a digital computer. Some computation results have been presented for a start-up of the vehicle.

	SIMULATION OF POWER-ELECTRONIC SYSTEMS - COMPUTATIONAL METHOD USING VARIABLE STEP By F. Bordry; D. Martins	[View] [Download]
Abstract: This paper presents a method for simulating switch-functioning semiconductor electric circuits. The method only requires knowledge of the circuit structure, its parameters and the control order of the semiconductors being controlled. Particular attention has been paid to the modelling of the semiconductors and particularly to the computation method. In the simulation program, the calculation step is variable, this is determined based on the time constants of the device. This original method allows to obtain a very high accuracy by in addition a short calculation time.