1,721,045 research outputs found
A Mechatronic Real-Time Model for Railway Vehicle Emulation
No full textThe Interoperability Technical Specification of European Railway led up the definition of new
standards to provide unified test procedures for all railway components. In particular, it is necessary to
perform traction and braking tests to verify the traction controller performance before entry into service.
To make less expensive and faster this procedures, which is carried out actually on real railway vehicles, a
new test bench, combining software with hardware in the loop, was developed. This paper presents the
new mechatronic real-time model of the railway vehicle used on this test bench to emulate the behaviour
of the real system
Emulazioni di veicoli ferroviari: un modello meccatronico real-time
No full textLa Specifica Tecnica di Interoperabilità tra le reti
ferroviarie europee ha portato alla definizione di
norme e procedure unificate per la verifica dei veicoli
ferroviari. In particolare, sono state previste prove
di trazione e frenatura in linea atte a valutare
le prestazioni dei controllori di trazione prima
dell’entrata in servizio dei veicoli ferroviari.
Tali prove utilizzano il veicolo ferroviario completo
e sono quindi costose e lunghe. Si propone un banco
prova innovativo che, emulando il comportamento
del veicolo ferroviario, esegue più velocemente
e in modo meno costoso le prove e si descrive il
modello meccatronico in tempo reale implementato
ELECTROMECHANICAL INTERACTION BETWEEN CARBON BASED PANTOGRAPH STRIP AND COPPER CONTACT WIRE: A HEURISTIC WEAR MODEL
Full text linkMain contributions to the wear in the sliding contact between pantograph's strip and catenary's wire can be classified as: i) mechanical contribution, due to friction, ii) electrical contribution, due to current flow at the contact and iii) electrical arcs contribution related to power dissipated during arc generation. In this work, a heuristic wear model for the contact wire, which accounts for the mentioned three main contributions to the wear, is presented. After a tuning phase with results obtained by an experimental campaign aimed at evaluating the wear for the couple “pure copper contact wire – Kasperovski contact strip”, the wear model is used in combination with a dynamical electromechanical model able to reproduce the electromechanical pantograph-catenary interaction
A procedure for the wear prediction of collector strip and contact wire in pantograph-catenary system
No full textThe effects of friction and electrical phenomena like arcing and sparking govern the wear rate in the sliding contact between the contactwire and the collectorstrip, these two effects are mutually interconnected in a complex manner. A means of investigating the wear of the collectorstrip and the contactwire is to carry out laboratory tests that allow to perform comparative tests between different material combinations and to establish the dependence on the main parameters such as sliding speed, contact force and current intensity. A problem to be considered in the application of the laboratory test results is their extrapolation to the real operating conditions, in order to assess the effective benefit among different solutions. In this paper, aprocedure that combines awear model for the contact between collectorstrip and contactwire with the simulation of the dynamic interaction between pantograph and catenary is proposed. The adopted wear model is based on the wear map concept, including the effect of electrical current flow, and it is tuned by means of the results obtained on laboratory test rig.
The dependence of the electrical contact resistance on the contact force between each contactstrip of the pantograph and the contactwire of the overhead line is considered and the corresponding electrical current on each of the two collectors of the pantograph is evaluated. Instantaneous values of contact forces and electrical current are then fed into the wear model and the amount of the wear of the collectorstrips and of the contactwire along the overhead line is calculated, generating an irregular profile of the contactwire.
The proposed procedure is applied to two cases: in the first one the wear of the contactwire using copper collectorstrips and graphite collectorstrips for dc line are compared. In the second one, the consequence of the variation of the mechanical tension of the contactwire on the wear levels is predicted
Mechatronics traction control design to improve the comfort of tyred electrical tramcar
No full textThis paper presents a mechatronics integrated
analysis and design of an electrical tramcar in order to optimize
system comfort performance.
The analysis is focused on a tyred electrical tramcar with a
direct self control of traction induction motors [1]. In this
system, wrong flux estimation at low speed causes unwanted
longitudinal acceleration variations, amplified by natural
frequencies of the vehicle tyres. The result of this phenomenon is
the deterioration of vehicle comfort.
The work includes an integrated simulation of mechatronics
system to compare different solutions and a modified flux
observer [2] to improve the vehicle comfort.
A final experimental test on a prototype tramcar has been
presented to validate the results
Feasibility Analysis of Monitoring Contact Wire Rupture in High-Speed Catenary Systems
Full text linkThe rupture of the contact wire (CW) of a railway overhead contact line (OCL or
catenary) is expected to be a rare event. However, when it occurs, and a pantograph transits
under the already broken section of the CW, this can have catastrophic consequences for
the pantograph which in turn can cause a further extension of the damaged portion on the
OCL with a consequent disruption in the service and cause there to be a long time before
the operating condition can be restored. Therefore, the prevention of such events through
effective catenary monitoring is gaining significant attention. The purpose of this work
is to investigate the feasibility of a monitoring system that can be installed at each end of
an OCL section which is able to detect the occurrence of a broken CW event, sending an
alert to the management traffic system, so as to stop the train traffic before the damaged
catenary is reached by other trains. A nonlinear dynamic analysis is employed to model
the OCL’s response following a simulated CW rupture and identify a set of variables that
can be measured at the line’s extremities related to the occurrence of breakage in the CW.
Several locations of the rupture of a CW section along the line are simulated to investigate
the influence on the time pattern of the measured variables and consequently on the
extraction of a signature. Finally, a proposed measurement setup is presented, combining
accelerometers and displacement transducers, instead of the direct measurement of the
axial load of the OCL conductors
A numerical 3D model to study ratcheting damage of a tramcar line
No full textA damaged rail may severely influence passenger comfort and the safety of the vehicles that run on it. The typical damages observed on rails are wear and cracks resulting from the dynamic interaction with vehicle wheels. In order to decrease the high costs borne by transportation authorities for track maintenance, predictive maintenance planning could prove to be very useful. This paper deals with a numerical three-dimensional (3D) model for the prediction of tramline rail damage phenomena. This model is not only useful in terms of planning maintenance and inspection intervals on the rails, but also enables to demonstrate how a specific tramcar vehicle influences rail damage, thus enabling to provide some suggestions regarding the design of tramcars that could have a less aggressive impact on the line. In this paper, starting from the contact forces due to the dynamic interaction between the wheels and the rails calculated by means of a multi-body model of tramcar vehicles, a ratcheting analysis of the rails was carried out. Although a specific running condition (i.e. a curved track with a 50 m radius) was analysed, the numerical 3D model is valid for general conditions and, in terms of impact on the line, can be used to evaluate the performance of existing and future tramcar vehicles
Electro-mechanical contact between pantograph strip and catenary contact wire: laboratory tests and wear model
No full textMain topics of this paper are the results obtained by a laboratory experimental campaign carried out to evaluate the electromechanical wear for the couple Cu-ETP contact wire – “Kasperovski” contact strip, where the carbon is encased in copper on three sides. In order to evaluate the evolution of the wear for the contact wire, a heuristic model is developed considering three main interacting contributions to wear in the case of pantograph-catenary interaction: i) the mechanical contribution, due to the friction; ii) the electrical contribution, due to power dissipation related to the Joule effect; iii) the electrical arcs contribution, due to the power dissipation generated by the electrical arcs that occur when the contact dynamics causes a contact loss
A real time environment for industial electrical drive control board testing
No full textThe development of electrical drives control
requires preliminary tests that could be very expensive and time
consuming due to the presence of implementation errors
especially in the first stage of the project. To avoid power
electronic, motor or load faults, alternative testing methods are
necessary. This paper presents a Hardware in the Loop (HIL)
real-time platform for the electrical drive control board testing
that meets this requirements. An object-oriented modeling
approach of electrical drives is presented in order to allow more
flexible simulation software structure and to improve the
integration speed. A comparison between HIL emulation results
and experimental results obtained using the same control on a
real induction motor drive is presented to validate the approach
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