EPE Association: EPE 1995 - 11 - Lecture Session L3c: TRACTION (I)

EPE 1995 - 11 - Lecture Session L3c: TRACTION (I)
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1995 - Conference > EPE 1995 - 11 - Lecture Session L3c: TRACTION (I)

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   NEW CONTROL CONCEPT FOR OVERLOAD MINIMIZED TRACTION DRIVES
By H.-P. Beck; B. Engel [View]
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Abstract: Torque oscillations occur in poorly damped drive trains of electrical high-speed locomotives due to the stochastic wheel-rail-contact. These reduce the life time of mechanical components. The drive train can be considered as three-mass-spring-system with two frequencies of natural torsion at approximately 20 Hz and 50 Hz. A conventional speed controller is able to damp only the first frequency to a limited extend. With the high-dynamic torque control and single-fed traction motors, it is possible to develop new control concept based on a state controller while taking the mechanical system into account. It shifts the poles of both natural oscillations in the negative real direction and increases the damping. As the control concept should not need more sensors than the conventional speed controlled AC drive, the missing states have to be reconstructed by an observer or a fllter. While a Luenberger observer is designed for reconstructing the system states after an initial disturbance, the Kalman filter is an optimal state estimator, if the process and the measurements involve permanent random perturbations. Simulation results with deterministic and stochastic load torques show that the state controller with Kalman filter reduces both oscillations of natural torsion and thereby increases the lifetime of mechanical components in the drive train.

   INVESTIGATING THE TRACTION DRIVE IN THE DEVELOPMENT OF A LOCOMOTIVE ADHESION CONTROLLER
By M. Stiebler; M. Lange; A. Gross-Thebing [View]
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Abstract: Traction drives for rail vehicles have to highly utilize the available adhesion. In existing simulation systems only simple models for the mechanical parts and especially the rolling contact are used. By a more exact modelling of the interactions between mechanical and electrical oscillations the comprehension of physical mechanisms is improved. With the results a control algorithm for a system optimized drive control featuring low rate of wear and lack of rail surface damage shall be developed.

   ACTIVE FILTERING OF TRACTION DRIVES FED BY DC CONTACT LINE
By R. Manigrasso; G. Superti Furga; E. Tironi; A. Farini [View]
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Abstract: Active filtering is a subject of interest because of the possibilities it offers of reducing the volume of passive filter on board rolling stock and limiting line current harmonics. The problem of the rating of active filters is more complex in rolling stock than industrial plants due to the characteristics of the supply, the power involved as well as the type of converters used. The complexity is also related to regulations concerning harmonic currents approved for traction: these do not appear to have been completely and rationally defmed yet. The scope of the paper is to show how the introduction of an active filter leads to choices which condition the design of the entire system and to present the design data and controls for the most promising solution.

   HIGH PERFORMANCE MULTISYSTEM LOCOMOTIVE E 412 FOR THE ITALIAN STATE RAILWAYS
By L. Morisi; F. Sezenna; L. Mantica; M. Oberti [View]
[Download]

Abstract: For the strengthening of the railway service on the connection Italy-Austria-Germany, FS ordered, at the end of 1993, 20 units of a new multi-voltage locomotive, called Class E412. The locomotive, having a full adhesion and a mass of 87 tons, is able to develop a continuous power at wheels of 6000 kW, until a speed of 200 km/h. The double star asynchronous motors are supplied at variable frequency and voltage by means of an oil-cooled GTO converter that allows service below 3 kV d.c. lines and under 15 kV 16 2/3 Hz lines. Service is also assured at reduced performance under a 1,5 kV d.c. line. During the d.c. operation, the main transformer assures also the function of line filter. In a.c. service, the transformer supplies a double-stage converter. In d.c. service, all the converter modules operate as inverters and each of them separately supplies one of the motor stars. This solution consents the maximum reduction of weight, though using single axle drive. The regenerative and/or rheostatic electric braking is able to work in d.c. and a.c. service. The control electronics, based on the MICAS S2 series, is an integrated and uniform system. Transmission of all machine signals on a redundant fibre-optics bus helps to reduce harness to a minimum and ensures noise-free operation. The locomotive is equipped with several diagnostic and remote control systems.

EPE 1995 - 11 - Lecture Session L3c: TRACTION (I)
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1995 - Conference > EPE 1995 - 11 - Lecture Session L3c: TRACTION (I)
	[return to parent folder]

	NEW CONTROL CONCEPT FOR OVERLOAD MINIMIZED TRACTION DRIVES By H.-P. Beck; B. Engel	[View] [Download]
Abstract: Torque oscillations occur in poorly damped drive trains of electrical high-speed locomotives due to the stochastic wheel-rail-contact. These reduce the life time of mechanical components. The drive train can be considered as three-mass-spring-system with two frequencies of natural torsion at approximately 20 Hz and 50 Hz. A conventional speed controller is able to damp only the first frequency to a limited extend. With the high-dynamic torque control and single-fed traction motors, it is possible to develop new control concept based on a state controller while taking the mechanical system into account. It shifts the poles of both natural oscillations in the negative real direction and increases the damping. As the control concept should not need more sensors than the conventional speed controlled AC drive, the missing states have to be reconstructed by an observer or a fllter. While a Luenberger observer is designed for reconstructing the system states after an initial disturbance, the Kalman filter is an optimal state estimator, if the process and the measurements involve permanent random perturbations. Simulation results with deterministic and stochastic load torques show that the state controller with Kalman filter reduces both oscillations of natural torsion and thereby increases the lifetime of mechanical components in the drive train.

	INVESTIGATING THE TRACTION DRIVE IN THE DEVELOPMENT OF A LOCOMOTIVE ADHESION CONTROLLER By M. Stiebler; M. Lange; A. Gross-Thebing	[View] [Download]
Abstract: Traction drives for rail vehicles have to highly utilize the available adhesion. In existing simulation systems only simple models for the mechanical parts and especially the rolling contact are used. By a more exact modelling of the interactions between mechanical and electrical oscillations the comprehension of physical mechanisms is improved. With the results a control algorithm for a system optimized drive control featuring low rate of wear and lack of rail surface damage shall be developed.

	ACTIVE FILTERING OF TRACTION DRIVES FED BY DC CONTACT LINE By R. Manigrasso; G. Superti Furga; E. Tironi; A. Farini	[View] [Download]
Abstract: Active filtering is a subject of interest because of the possibilities it offers of reducing the volume of passive filter on board rolling stock and limiting line current harmonics. The problem of the rating of active filters is more complex in rolling stock than industrial plants due to the characteristics of the supply, the power involved as well as the type of converters used. The complexity is also related to regulations concerning harmonic currents approved for traction: these do not appear to have been completely and rationally defmed yet. The scope of the paper is to show how the introduction of an active filter leads to choices which condition the design of the entire system and to present the design data and controls for the most promising solution.

	HIGH PERFORMANCE MULTISYSTEM LOCOMOTIVE E 412 FOR THE ITALIAN STATE RAILWAYS By L. Morisi; F. Sezenna; L. Mantica; M. Oberti	[View] [Download]
Abstract: For the strengthening of the railway service on the connection Italy-Austria-Germany, FS ordered, at the end of 1993, 20 units of a new multi-voltage locomotive, called Class E412. The locomotive, having a full adhesion and a mass of 87 tons, is able to develop a continuous power at wheels of 6000 kW, until a speed of 200 km/h. The double star asynchronous motors are supplied at variable frequency and voltage by means of an oil-cooled GTO converter that allows service below 3 kV d.c. lines and under 15 kV 16 2/3 Hz lines. Service is also assured at reduced performance under a 1,5 kV d.c. line. During the d.c. operation, the main transformer assures also the function of line filter. In a.c. service, the transformer supplies a double-stage converter. In d.c. service, all the converter modules operate as inverters and each of them separately supplies one of the motor stars. This solution consents the maximum reduction of weight, though using single axle drive. The regenerative and/or rheostatic electric braking is able to work in d.c. and a.c. service. The control electronics, based on the MICAS S2 series, is an integrated and uniform system. Transmission of all machine signals on a redundant fibre-optics bus helps to reduce harness to a minimum and ensures noise-free operation. The locomotive is equipped with several diagnostic and remote control systems.