EPE Association: EPE 1987 - 36 - Late Papers 1.1: LATE PAPERS

EPE 1987 - 36 - Late Papers 1.1: LATE PAPERS
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1987 - Conference > EPE 1987 - 36 - Late Papers 1.1: LATE PAPERS

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   COMPARISON OF THREE 4500V- 2500A GTO
By R. Lallemand; G. Debled [View]
[Download]

Abstract: Using 4500 V - 2500 A GTO allows to build traction devices for 1500 V. D.C. lines with one component for one arm. This advantage, cumulated with a simplified schema, decreasas the number of power components by a factor 4 to 6. As it is difficult to compare big GTO only from their data sheets, tests have been made in one same shopper with 2 japanese and 1 european GTO, 4500 V - 2500 A. Tests results are presented and the necessary modifications of the trigger device are discussed together with effects of decreasing the snubber capacity.

   CONTROL STRATEGIES IN AC-AC FREQUENCY CONVERTERS FOR INDUCTION HEATING
By J.E. Quaicoe [View]
[Download]

Abstract: Direct ac-ac frequency converters employed in induction heating applications are normally operated using one of three control schemes namely, the forced commutation scheme, the unclamped scheme and the clamped scheme. This paper reviews the basic performance characteristics of the six-pulse ac-ac frequency converter operating under the three control schemes. Ideal waveforms describing the operation of the converter with a resistive load and generalized analytical expressions derived from equivalent circuits of the converter are presented. On the basis of the waveforms and analytical expressions, the basic operating characteristics of the frequency converter are described for the three control schemes. The paper shows that the clamped scheme offers the advantages of reduced output current distortion and an output power control through frequency control as opposed to phase control.

   DIRECT COOLING FOR BIG GTO
By G. Coquery [View]
[Download]

Abstract: Using 50 to 75 mm GTO allows a reduction of the number of power components and of total losses in traction equipment. However, the GTO itself is uneasy to cool due to surface reduction of his cathode and mechanical difficulties for its correct pressing. Also, having concentrated losses in one component, arises problems to spread them over the surface of big fins. A special device, adapted to these requirements, is presented. It allows to fix an isolated GTO, without liquids, into one single faced fin. The tests have been performed up to 1500 W losses for a 50 mm component.

   ELECTRICAL DRIVE CONTROL OF AN ARTIFICIAL HEART
By Marcel Jufer; Razack Osseni; Guy Füllemann [View]
[Download]

Abstract: This totally implantable artificial heart developed by us is characterized by a double pusher-plate system, moving two sacks corresponding to both ventricles. The transformation of the rotating movement of the motor in the linear pusher-plates displacement is realized by a planetary roller-screw. The chosen electrical motor is a brushless DC one, characterized by high performances integrated components. The PM are directly fixed on the screw nut, which is the rotor yoke, in order to reduce the total system inertia. The paper describes the main characteristics of the motor, the power electronics and the control. The artificial heart has been implanted several times on animals.

   SEMICONDUCTOR CONVERTER PROTECTION AGAINST LONG DURATION OVERVOLTAGES APPEARING IN SUPPLY SOURCES
By W. Koczara; Z. Szulc [View]
[Download]

Abstract: In the paper is presented mathematical analysis, operational principles and experimental results of a power-electronics system for damping overvoltages apearing in the electrical power source, feeding power electronic loads. Considering a simplified mathematical model of a choosen electric power source, various disturbances are shown such as overvoltages that can apear on its output. Further analysis considers decreasing those overvoltages by a damping resister connected to such source by a thyristor coupler. The relationships between the overvoltage parameters and the resistor values is also shown.

   RAILWAY TRACTION POWERED BY SYNCHRONOUS MOTORS SUPPLIED THROUGH NATURAL COMMUTATION INVERTERS
By Albert Wiart; Jean Hamel [View]
[Download]

Abstract: The advantages of these drives may be implemented in railway traction as well as in industrial application. In traction, there are more demanding requirements with respect to the magnitude and the regularity of the torque at start-up and very low speeds. The drives must also work on various power supplies e.g. A.C. and D.C. currents. Some simple arrangements can meet these requirements. The diagrams of different simple systems meeting these requirements are presented and their operation described. Examples of some outstanding achievements are given both in industrial and railway traction applications.

   RESEARCH AND DEVELOPMENT OF URBAN COMMERCIAL ELECTRIC VEHICLES
By F. Tonnerieux; C. Glaize; R. Berlioux [View]
[Download]

Abstract: The availability of new Ni-Fe and Ni-Zn batteries has given a new interest to research on electric vehicles. We present a small utility van using such batteries. We explain the choice of the motor, its supply and their control. Experimental results are presented.

   DESIGN, TYPE TESTS AND FIELD TESTS OF THE CONVERTERS FOR THE 2000 MW HVDC CROSS-CHANNEL LINK
By P. Charles; B. Depommier; A. Riguet [View]
[Download]

Abstract: This paper describes the design of the 270 kV 500 MW French converters for the new 2000 MW direct-current link between France and Great-Britain. The cooling system, the thyristor valve firing system, the overvoltage protection using zinc-oxide arresters, and the electrical connections in the valve hall are discussed. Some emphasis is placed on type and field testing of the converters in terms of performance.

   COMPUTER REPRESENTATION OF TRACTION CHOPPER FOR HARMONIC ANALYSIS
By A. Piccolo; N. Rotondale [View]
[Download]

Abstract: The problem of harmonic pollution due to traction chopper is analyzed in order to have a large amount of informations which take into account also random variations. At this aim, firstly the behaviour of a classical chopper for dc traction is examined, with emphasys on the harmonic content and on the links between chopper current and control logic. Then a harmonic model of the traction chopper is proposed. lt takes into account the presence of non-ideal operating conditions, deriving from late or early firings. Finally it is shown how the proposed model well fits in a probabilistic approach, which seems to be particularly suitable for evaluating current distortion in de traction systems.

   HVDC SIMULATOR FOR ENGINEERING STUDIES
By R. Beaussier; P. Charles [View]
[Download]

Abstract: This paper presents a new real-time simulator built for engineering studies of thyristor systems in power transmission applications. Studies of HVDC converter and SVC performance characteristics, and the dynamic interaction with the HVAC system are the main uses of this simulator. The power system is modelled at a very low power scale. All electrical components (transformers, lines, filters, valves and machines) are built from analog electronic circuits with programmable adjustment of the main parameters. An intensive test campaign bas been carried out to investigate the compatibility between models and the influence of operational amplifier performance. Stability, bandwidth, losses and offset have been characterized. The simulator control system (data acquisition system, sequence controller and configuration designer) bas been paid special attention at the design stage to achieve high flexibility and operating performance.

EPE 1987 - 36 - Late Papers 1.1: LATE PAPERS
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1987 - Conference > EPE 1987 - 36 - Late Papers 1.1: LATE PAPERS
	[return to parent folder]

	COMPARISON OF THREE 4500V- 2500A GTO By R. Lallemand; G. Debled	[View] [Download]
Abstract: Using 4500 V - 2500 A GTO allows to build traction devices for 1500 V. D.C. lines with one component for one arm. This advantage, cumulated with a simplified schema, decreasas the number of power components by a factor 4 to 6. As it is difficult to compare big GTO only from their data sheets, tests have been made in one same shopper with 2 japanese and 1 european GTO, 4500 V - 2500 A. Tests results are presented and the necessary modifications of the trigger device are discussed together with effects of decreasing the snubber capacity.

	CONTROL STRATEGIES IN AC-AC FREQUENCY CONVERTERS FOR INDUCTION HEATING By J.E. Quaicoe	[View] [Download]
Abstract: Direct ac-ac frequency converters employed in induction heating applications are normally operated using one of three control schemes namely, the forced commutation scheme, the unclamped scheme and the clamped scheme. This paper reviews the basic performance characteristics of the six-pulse ac-ac frequency converter operating under the three control schemes. Ideal waveforms describing the operation of the converter with a resistive load and generalized analytical expressions derived from equivalent circuits of the converter are presented. On the basis of the waveforms and analytical expressions, the basic operating characteristics of the frequency converter are described for the three control schemes. The paper shows that the clamped scheme offers the advantages of reduced output current distortion and an output power control through frequency control as opposed to phase control.

	DIRECT COOLING FOR BIG GTO By G. Coquery	[View] [Download]
Abstract: Using 50 to 75 mm GTO allows a reduction of the number of power components and of total losses in traction equipment. However, the GTO itself is uneasy to cool due to surface reduction of his cathode and mechanical difficulties for its correct pressing. Also, having concentrated losses in one component, arises problems to spread them over the surface of big fins. A special device, adapted to these requirements, is presented. It allows to fix an isolated GTO, without liquids, into one single faced fin. The tests have been performed up to 1500 W losses for a 50 mm component.

	ELECTRICAL DRIVE CONTROL OF AN ARTIFICIAL HEART By Marcel Jufer; Razack Osseni; Guy Füllemann	[View] [Download]
Abstract: This totally implantable artificial heart developed by us is characterized by a double pusher-plate system, moving two sacks corresponding to both ventricles. The transformation of the rotating movement of the motor in the linear pusher-plates displacement is realized by a planetary roller-screw. The chosen electrical motor is a brushless DC one, characterized by high performances integrated components. The PM are directly fixed on the screw nut, which is the rotor yoke, in order to reduce the total system inertia. The paper describes the main characteristics of the motor, the power electronics and the control. The artificial heart has been implanted several times on animals.

	SEMICONDUCTOR CONVERTER PROTECTION AGAINST LONG DURATION OVERVOLTAGES APPEARING IN SUPPLY SOURCES By W. Koczara; Z. Szulc	[View] [Download]
Abstract: In the paper is presented mathematical analysis, operational principles and experimental results of a power-electronics system for damping overvoltages apearing in the electrical power source, feeding power electronic loads. Considering a simplified mathematical model of a choosen electric power source, various disturbances are shown such as overvoltages that can apear on its output. Further analysis considers decreasing those overvoltages by a damping resister connected to such source by a thyristor coupler. The relationships between the overvoltage parameters and the resistor values is also shown.

	RAILWAY TRACTION POWERED BY SYNCHRONOUS MOTORS SUPPLIED THROUGH NATURAL COMMUTATION INVERTERS By Albert Wiart; Jean Hamel	[View] [Download]
Abstract: The advantages of these drives may be implemented in railway traction as well as in industrial application. In traction, there are more demanding requirements with respect to the magnitude and the regularity of the torque at start-up and very low speeds. The drives must also work on various power supplies e.g. A.C. and D.C. currents. Some simple arrangements can meet these requirements. The diagrams of different simple systems meeting these requirements are presented and their operation described. Examples of some outstanding achievements are given both in industrial and railway traction applications.

	RESEARCH AND DEVELOPMENT OF URBAN COMMERCIAL ELECTRIC VEHICLES By F. Tonnerieux; C. Glaize; R. Berlioux	[View] [Download]
Abstract: The availability of new Ni-Fe and Ni-Zn batteries has given a new interest to research on electric vehicles. We present a small utility van using such batteries. We explain the choice of the motor, its supply and their control. Experimental results are presented.

	DESIGN, TYPE TESTS AND FIELD TESTS OF THE CONVERTERS FOR THE 2000 MW HVDC CROSS-CHANNEL LINK By P. Charles; B. Depommier; A. Riguet	[View] [Download]
Abstract: This paper describes the design of the 270 kV 500 MW French converters for the new 2000 MW direct-current link between France and Great-Britain. The cooling system, the thyristor valve firing system, the overvoltage protection using zinc-oxide arresters, and the electrical connections in the valve hall are discussed. Some emphasis is placed on type and field testing of the converters in terms of performance.

	COMPUTER REPRESENTATION OF TRACTION CHOPPER FOR HARMONIC ANALYSIS By A. Piccolo; N. Rotondale	[View] [Download]
Abstract: The problem of harmonic pollution due to traction chopper is analyzed in order to have a large amount of informations which take into account also random variations. At this aim, firstly the behaviour of a classical chopper for dc traction is examined, with emphasys on the harmonic content and on the links between chopper current and control logic. Then a harmonic model of the traction chopper is proposed. lt takes into account the presence of non-ideal operating conditions, deriving from late or early firings. Finally it is shown how the proposed model well fits in a probabilistic approach, which seems to be particularly suitable for evaluating current distortion in de traction systems.

	HVDC SIMULATOR FOR ENGINEERING STUDIES By R. Beaussier; P. Charles	[View] [Download]
Abstract: This paper presents a new real-time simulator built for engineering studies of thyristor systems in power transmission applications. Studies of HVDC converter and SVC performance characteristics, and the dynamic interaction with the HVAC system are the main uses of this simulator. The power system is modelled at a very low power scale. All electrical components (transformers, lines, filters, valves and machines) are built from analog electronic circuits with programmable adjustment of the main parameters. An intensive test campaign bas been carried out to investigate the compatibility between models and the influence of operational amplifier performance. Stability, bandwidth, losses and offset have been characterized. The simulator control system (data acquisition system, sequence controller and configuration designer) bas been paid special attention at the design stage to achieve high flexibility and operating performance.