This paper aims to provide an overview of the present status of research in pantograph–overhead line interaction and to outline future research challenges. A review of currently used modelling and simulation approaches is provided, also including hybrid simulation, and emerging trends are outlined. Then, line testing methods for the certification of pantographs and catenaries are described and the limitations of measuring methods now in use are highlighted. Issues related to the reliability and availability of the pantograph–overhead line system and to life-cycle costs are then covered in the paper, particularly concerning wear and other damage phenomena and condition monitoring solutions enabling the efficient maintenance of the system. Pantograph aerodynamics and active control of pantographs are finally identified as two emerging trends of research. For both subjects, a review of problems currently at stake and of future research directions is provided.

Most of the high-speed trains in operation today have the electrical power supply delivered through the pantograph-catenary system. The understanding of the dynamics of this system is fundamental since it contributes to decrease the number of incidents related to these components, to reduce the maintenance and to improve interoperability. From the mechanical point of view, the most important feature of the pantograph-catenary system consists in the quality of the contact between the contact wire of the catenary and the contact strips of the pantograph. The catenary is represented by a finite element model, whereas the pantograph is described by a detailed multibody model, analysed through two independent codes in a co-simulation environment. A computational procedure ensuring the efficient communication between the multibody and finite element codes, through shared computer memory, and suitable contact force models were developed. The models presented here are contributions for the identification of the dynamic behaviour of the pantograph and of the interaction phenomena in the pantograph-catenary system of high-speed trains due to the action of aerodynamics forces. The wind forces are applied on the catenary by distributing them on the finite element mesh. Since the multibody formulation does not include explicitly the geometric information of the bodies, the wind field forces are applied to each body of the pantograph as time-dependent nonlinear external forces. These wind forces can be characterised either by using computational fluid dynamics or experimental testing in a wind tunnel. The proposed methodologies are demonstrated by the application to real operation scenarios for high-speed trains, with the purpose of defining service limitations based on train and wind speed combination

The mathematical model of suspension components in a railway vehicle may have an important effect on the results of vehicle dynamics simulations and their accuracy in reproducing the actual vehicle behaviour. This paper aims to define and compare alternative mathematical modelling approaches for the secondary airspring suspension and to assess their effect on the accuracy of rail vehicle dynamics multibody simulation. To derive reliable models of the suspension, a quasi-static and dynamic characterisation of the suspension was performed by means of a full-scale laboratory experiment. Based on this, two different modelling approaches were developed for the airspring suspension: a quasi-static one, in which the frequency-dependent behaviour of the suspension is neglected, but the coupling between shear and roll stiffness is included, and a dynamic one in which additionally the frequency-dependent behaviour of the suspension in vertical direction is represented using a thermodynamic model, and additionally the dependency of lateral/roll stiffness parameters on the load is incorporated. The results of vehicle dynamics simulations in curved track and/or in the presence of crosswinds and the results of ride comfort calculations are presented, to assess the effect of the models developed, in comparison with a simpler model only reproducing the vertical and lateral stiffness of the suspension. It is demonstrated that the quasi-static coupling effect between shear and roll deformation in the airsprings can have a large effect on the simulation of load transfer effects in curved track and in the presence of crosswinds, and hence remarkably affect the assessment of ride safety and track loading, whereas the dynamic model of the airspring suspension appears to be required when wheel unloading under the action of crosswind is evaluated. Finally, it is shown that a dynamic model of the airspring is required to assess ride comfort correctly, especially when the pneumatic layout of the suspension includes a long pipe between the airspring and the reservoir.

Pantograph active control is considered as a means to improve the current collection quality in high-speed railways. Different studies have focused on the assessment of pantograph control systems, addressing actuator configurations and control strategies, mainly by means of numerical experiments. In the last few years, it has become possible to transfer the knowledge gained from numerical experiments to real operating conditions. Due to the high cost of on-track tests, which are necessary for the final assessment of active pantograph performances, it is desirable to perform these tests on a system that has already demonstrated its capabilities with less expensive laboratory tests, in which at least the basic features of the real operating conditions are reproduced. This paper deals with the development of a hardware-in-the-loop (HIL) test rig, which allows the reproduction of the dynamical interaction between the overhead lines and the pantograph in high-speed railways. The HIL test rig makes it possible to verify the control strategies, the electrical drive configurations for active control, and the contact force estimation procedures on a real pantograph under conditions that are similar to those encountered on the real line. Some examples of test bench applications for pantograph active control and contact force estimation are also presented.

Hardware-in-the-loop (HIL) simulation is a promising technique to study the pantograph–catenary interaction problems by realising the interaction of a physical pantograph with a mathematical model of the overhead equipment (catenary). However, the computing power presently available on real-time CPUs only allows to run simplified models of the overhead equipment. Therefore, it is important to define catenary models that are suitable for real-time simulation and at the same time capable of accurately representing the dynamic behaviour of the catenary. In this paper, the use of a catenary model based on modal superposition is considered, and the effect of changing the number of modelled spans and the number of modal components allocated to the contact and messenger wires is investigated in view of finding the best model compatible with real-time simulation. Comparisons between HIL simulation results and line measurements are presented, to quantify the accuracy of the hybrid simulation method developed.