Keywords: dynamics, simulation, pantograph, catenary, finite element, design.

This paper deals with the pantograph-catenary interface, which represents one of the most critical interfaces of the railway system, especially for the multiple unit operation. Indeed, the pantograph-catenary system is generally the first blocking point when increasing the train speed. Thios is due to the phenomenon known as the "catenary barrier", in reference to the sound barrier. It refers to the fact that when the train speed reaches the propagation speed of the flexural waves in the contact wire a singularity emerges, creating a particularly high level of fluctuations in the contact wire. When operating in a multiple unit configuration, the pantograph-catenary system is even more critical, since the trailing pantograph(s) experiences a catenary that is already swaying due to the passage of the leading pantograph.

Since 1984, SNCF has been developing finite element software to simulate the pantograph-catenary dynamics. The last software, named OSCAR (Outil de Simulation du CAptage pour la Reconnaissance des défauts), is a fully three-dimensional software that permits the representation of any kind of catenary system (simple or compound catenary, with or without stitch wire, tramway contact lines, etc.). It takes into account all non-linearities present in the system: bumpstops, friction elements in the pantograph; non linear droppers in the catenary; and contact losses at the interface. It also manages the wave propagation and the coupling of flexible structures through a load moving on a finite element mesh.

In the first part, the mechanical specifications of the pantograph-catenary system will be presented, and the way that the software deals with them will be detailed.

In the second part, simulation will be used to investigate specific phenomena such as:

• the critical speeds related to the ratio between the train speed and the wave propagation speed;
• the critical speeds linked to the resonance of the pantograph at the frequency of the catenary poles passage; and
• the critical speeds linked to the distance between the pantographs.

In the third part, simulation will be used to optimise a pantograph. Based on a sensitivity analysis, optimal parameters will be deduced and innovative suspensions will be proposed.

In the last part, an example of catenary system optimisation will be presented. As for the pantograph optimisation, the sensitive parameters will be extracted and a cost-based optimum will be deduced. Some innovations based on damping elements will be proposed to improve current collection in a multiple unit.

purchase the full-text of this paper (price £20)

go to the previous paper
go to the next paper
return to the table of contents
return to the book description
purchase this book (price £145 +P&P)