Influence of Pantograph Components on the Contact Quality of the Overhead System for High Speed Trains

The pantograph-catenary system is still the most reliable form of collecting electric energy for running trains. Nevertheless, the interaction between the moving rolling stock and the overhead contact line is one of the factors that limits the operating speed of railway vehicles and, consequently, is one of the research priorities in the railway community. These limitations concern not only the ability to collect energy at high speeds but also address the interoperability of the overhead equipment. The pantograph-catenary system should ideally run with relatively low contact forces, in order to minimize wear and damage of the contacting elements, but with high enough forces to prevent contact loss, which interrupts the power supply and promotes the occurrence of electric arcing. Therefore, the design of these systems aims at controlling the pantograph-catenary interaction maintaining the contact forces within admissible operational intervals.

The work presented here aims at enhancing the understanding of the pantograph-catenary contact phenomena by identifying the key parameters, associated with the pantograph, that affect the interaction forces. A multibody formulation is used to model the pantograph and the catenary is modelled in a linear finite element code. By using a validated co-simulation procedure the dynamics of the pantograph is effectively coupled with that of the catenary, representing the complete system interaction [1,2]. A range of relevant interoperable design configurations of the pantograph are considered, including their geometric and mechanical features such as masses, springs and dampers.

The numerical simulations performed here involve varying the pantograph parameters in a range of ± 10%, comparing the contact forces against the ones obtained with the nominal case and discussing the results. These studies can be viewed as a sensitivity analysis for the pantograph components, which enable an assessment of how much a variation of a mass, stiffness or damping property affects the contact quality of the overhead power system. The analyses are carried out for high speed trains running at velocities of 200, 250, 300 and 350 km/h. The influence of the modelling parameters on the pantograph-catenary interaction were assessed according to the European standards. In this regard, the characteristics of the contact forces and the loss of contact events were studied with detail.

The results presented in this paper show that the most important factor influencing the pantograph-catenary interaction is the trainset speed. With respect to the pantograph components, it is observed that the static contact force, exerted upwards by the pantograph head on the overhead contact line, is the most relevant one. However smaller, influences are also observed when varying the masses, springs and dampers of the pantograph model.