Extending pantograph dynamics assessment in laboratory to the evaluation of dynamic performances in real operating environment

The dynamic interaction between pantograph and overhead line (OHL) heavily influences the quality of the current collection that, on one side assures the correct power transmission from the contact wire to the electrical traction drives of the vehicle, and on the other side affects the amount of wear of both the contact wire of the OHL and the collector strips of the pantograph. Moreover the dynamics of pantograph-catenary coupled system is a mandatory topic when considering the interoperability issues, among which there is the requirement of the assessment of the quality of interaction between a pantograph running on a catenary belonging to a network different from its original one. Usually a pantograph is optimised and set-up for a given category of OHL, but it is not assured that running under different catenaries allows to obtain the same performances. To this purpose the key option is to perform test runs. Nevertheless an analysis before test trials would be very useful for a first evaluation of a new pantograph-OHL combination, enabling to save time and cost of the experimental runs. A first possibility, nowadays widely used especially in the design stage of new catenaries, is to perform numerical simulations by means of a validated numerical model, e.g. according to EN50318. As an auxiliary option, a hardware in the loop (HIL) indoor set-up can be used in order to analyse the dynamic behaviour of a real pantograph coupled with a overhead line (OHL), virtually simulated in real time. This work focuses on the analysis of the correspondences between indoor test carried out on a pantograph, and the results that are obtained during test runs on the real line. The laboratory tests are fundamentally of two types: classical sinusoidal tests (step sine or sweep sine) and tests with HIL set-up. The results of both approaches are compared with on track test results considering the influence pantograph mean contact force and contact wire mechanical tension. The potentialities of HIL approach as a useful tool for an effective application of the virtual homologation concept are pointed out.