Pantograph-catenary Interaction Research Articles

Hardware-in-the-loop hybrid simulation of pantograph–catenary interaction

The paper addresses the use of hybrid simulation to study pantograph-catenary interaction. Based on this approach, also known as ‘Hardware-in-the-loop’, a physical pantograph is set in interaction with a numerical model of the catenary which is run in real time. To this aim, a dedicated test bench was designed and built to reproduce pantograph–catenary interaction in the 0–20Hz frequency range also including the effect of stagger in the contact wire. To appraise the accuracy of the simulation method, results of hybrid simulations were compared with line test measurements, considering two different pantograph–catenary couples presently used in the European high-speed railway network.

Analysis of electrical interferences related to the current collection quality in pantograph–catenary interaction

The dynamic interaction between a pantograph and a catenary influences the quality of the current collection; in particular, when two pantographs are used to collect current, the second pantograph is subjected to the disturbances originated on the overhead line by the transit of the first pantograph, generally causing a deterioration of current collection quality. Under these conditions, the occurrence of continuous sparking, contact loss, and arcing cause an increase of wear for both contact wire and collector strips, but also cause variations of contact voltage and feed current that in turn produce interferences on the on-board electrical systems like drive motors and signalling system. In order to investigate the latter, a procedure for the correlation of the quality of current collection with the level of electrical interference is proposed in this article. The procedure is based on experimental and numerical models combining relationships obtained by means of laboratory tests with simulation tools. An application to a real case of double pantograph collection is presented.

Optical Fiber Sensors to Measure Collector Performance in the Pantograph-Catenary Interaction

Optical fiber sensors are proposed to detect static and dynamic collector strain for high-speed railway pantograph achieving electromagnetic immunity, nonelectrically conducting and small size. The implemented scheme based on a Michelson's interferometer with a 3 times 3 coupler allows local strain measurement insensitive to temperature variations with high reliability guaranteed by the employment of standard 1550 nm optical communications components. By a test rig to experimentally simulate the pantograph-catenary contact-force the sensor performance is compared with typical electric measurement.

A high performance tool for the simulation of the dynamic pantograph–catenary interaction

In this paper a computer tool for the simulation of the dynamic pantograph–catenary interaction is presented. We model this interaction and study its behavior in the energy transmission process. The calculation of the dynamic equation of the pantograph–catenary interaction is considered from a simulation point of view by means of a high performance computing algorithm, where the amount of data and the time requirements have been dramatically reduced. Finally, the present algorithm has been used to implement an user-friendly, interactive and graphically oriented toolbox whose design is presented in this work. This tool is used for the static and dynamic analysis of a catenaries system, which is shown by means of a real case of study.

Dynamic analysis using finite elements to calculate the critical wear section of the contact wire in suburban railway overhead conductor rails

The purpose of this study is to determine the critical wear levels of the contact wire of the catenary on metropolitan lines. The study has focussed on the zones of contact wire where localized wear is produced, normally associated with the appearance of electric arcs. To this end, a finite element model has been developed to study the dynamics of pantograph—catenary interaction. The model includes a zone of localized wear and a singularity in the contact wire in order to simulate the worst case scenario from the point of view of stresses. In order to consider the different stages in the wire wear process, different depths and widths of the localized wear zone were defined. The results of the dynamic simulations performed for each stage of wear let the area of the minimum resistant section of the contact wire be determined for which stresses are greater than the allowable stress. The maximum tensile stress reached in the contact wire shows a clear sensitivity to the size of the local wear zone, defined by its width and depth. In this way, if the wear measurements taken with an overhead line-recording vehicle are analysed, it will be possible to calculate the potential breakage risk of the wire. A strong dependence of the tensile forces of the contact wire has also been observed. These results will allow priorities to be set for replacing the most critical sections of wire, thereby making maintenance much more efficient. The results obtained show that the wire replacement criteria currently borne in mind have turned out to be appropriate, although in some wear scenarios these criteria could be adjusted even more, and so prolong the life cycle of the contact wire.

Contact Model for The Pantograph-Catenary Interaction

In the great majority of railway networks the electrical power is provided to the locomotives by the pantograph-catenary system. The single most important feature of this system consists in the quality of the contact between the contact wire(s) of the catenary and the contact strips of the pantograph. The work presented here proposes a new methodology to study the dynamic behavior of the pantograph and of the interaction phenomena in the pantograph-catenary system. The catenary is described by a detailed finite element model while the pantograph is described by a detailed multibody model. The dynamics analysis of each one of these models uses different time integration algorithms: the finite element model of the catenary uses a constant time step Newmark type of integration algorithm while the multibody model uses a variable order and variable time step Gear integration algorithm. The gluing element between the two models is the contact model, it is through the representation of the contact and of the integration schemes applied to the referred models that the needed co-simulation is carried on. The work presented here proposes an integrated methodology to represent the contact between the finite element and multibody models based on a continuous contact force model that takes into account the co-simulation requirements of the integration algorithms used for each subsystem model. The discussion of the benefits and drawbacks of the proposed methodologies and of their accuracy and suitability is supported by the application to the real operation scenario considered and the comparison of the obtained results with experimental test data.

Pantograph aerodynamic effects on the pantograph–catenary interaction

Some aspects about the influence on the current collection of the aerodynamic action on a pantograph, due to the incoming flow generated by train speed are investigated considering pantograph–catenary dynamic interaction. Starting from the quasi-steady theory formulation of the drag and lift forces on the collectors, and considering the turbulence of the incoming flow, the dynamic variation of the contact force between pantograph and catenary is taken into account, within an already developed simulation model. Aerodynamic coefficients of the collectors are obtained from wind tunnel measurements, and the aerodynamic forces are applied to the collectors of the pantograph. The interrelation among the geometry of the collector suspension, the collector shape, and the level of the incoming wind turbulence, and their effect on the contact force, are all considered in this article by means of numerical simulation. Results concerning the advantage of modifying the shape of the collector are outlined.

On the prediction of wear of contact wire in OHE lines: a proposed model

SUMMARYThe main features of a procedure for the prediction of the wear of contact wire in overhead equipment for railway traction is presented. The procedure is based on the simulation of pantograph-catenary dynamic interaction, coupled with a wear model of the contact wire. The wear model takes into account, in a first approximation, the electrical and mechanical contribution to wear, generating a worn contact wire profile, introduced as wire irregularity for subsequent simulations. In this way, it is possible to follow the evolution of wear, considering each simulation representative of a given number of pantograph passages.

Modelling and simulation of catenary-pantograph interaction

SUMMARYModelling and simulation of the dynamic behaviour of catenary-pantograph interaction is an important part when assessing the capability of a current collection system for railway traffic. The large variation in infrastructure characteristics in different countries and railway companies, different types of traffic, designs of pantographs etc. makes it almost impossible to develop a final simulation model of such a system. Instead, it would be favourable to have a tool that has the ability to set up models of such systems, choose relevant detail of the models, run simulations and finally visualise the results. To make the tool useful for engineers, design experts as well as simulation experts, the functionality of the tool must be worked out. Aspects on computer simulation such as developed models, simulation methods and computer tools are presented. The aim is to develop a scenario that considers different designs, models, solution methods and user levels. The scenario focuses on how to structure the use of simulation of dynamics in catenary-pantograph development. A scenario is sketched built on different user levels, a modular structure and a structure for information management.

High Speed Railways: Pantograph And OverheadLines Modelling And Simulation

The paper describes some aspects of the researches carried out on the subject of pantograph-catenary interaction at the Department of Mech. Eng. of Politecnico di Milano. In particular a mathematical model of pantograph and overhead equipment dynamic interaction has been developed, and validated by means of comparison with experimental results. The model has been used for the design of the italian high speed line, and for preliminary studies on the subject of active controlled pantograph.

Effect of Locomotive Vibrations on Pantograph-Catenary System Dynamics

An interactive model is developed to simulate dynamic behavior of pantograph-catenary systems. Vibrating responses of locomotive roof are directly inputted as excitations to the pantograph, which are obtained with the locomotive-track coupling dynamic model. Effect of locomotive vibrations on pantograph-catenary interactions is investigated for various cases. It is shown that the influence of locomotive vibrations upon the pantograph-catenary system dynamics is not negligible if the track geometric condition is not good, especially in high speed operation.