Metodología y desarrollo de herramientas para el estudio de la interacción pantógrafo catenaria a través de modelos virtuales y su aplicación a sistemas de catenaria rígida

Abstract

Main objective that has been set for the development of this thesis is the generation of a knowledge base on catenary systems. Most of the effort will be focused on overhead contact rails through the generation of a simulation tool that reproduces the interaction between the pantograph of a train and overhead catenary infrastructure. The development of this document has been oriented towards the contribution of three pillars: theoretical, methodological and practical. The theoretical contribution aside from the unification in the same text of the general descriptions of catenary systems is the identification of the necessary parameters for the development of simulations of the contact of two components that are in relative movement at high speeds. Regarding the applied methodology, the absence of specific regulations on overhead contact rail systems has forced the generation of alternative procedures based on similar physical processes and their extrapolation to the specific problem of the overhead contact rail. In these terms, a highly versatile tool has been produced. This tool offers results that are proven to be adjusted to different electrification systems. Finally, and as a result of the studies carried out during the first years, a technological contribution of practical application on overhead contact rail systems has been generated, which has obtained the granting of a patent through objective examination, demonstrating that the understanding of the physical process allows the development of technological alternatives that may improve the operation. The analysis of the existing regulations in relation to catenary systems shows a lack of standardization on overhead contact line systems. Its use has spread over the recent years especially in underground infrastructure. This has linked the overhead contact rail systems mainly to underground infrastructure inside cities, but there are exceptions in which the overhead contact rail systems are used outdoors or on High Speed infrastructure. The absence of regulatory texts at the time of starting the studies is sufficient proof of the need to develop a tool that provides a system for calculating the interaction between catenary components, regardless of whether it is flexible or rigid. Starting from the descriptions of the existing catenary systems and their components two simulation models based on significantly different technologies have been developed. On the one hand, a CAD software has been used, widely used for the study of the physical behavior of mechanisms and components. On the other hand, a simplified model has been developed based on Matlab applying the theory of structures and multibody studies of mechanisms. Both models have required the application of simplifications focused mainly on reducing the volume of calculations necessary to solve the dynamic problem. In both cases FEM has been applied, which has made it possible to establish a series of comparisons in terms of simulation quality, both for static and dynamic processes. In this sense, there has also been possible to access to the ADIF facilities at the Center for Railway Technologies located in Malaga, where there is a reproduction of an overhead contact rail section just like the one installed in the tunnel that joins the stations of Atocha and Chamartín in the city of Madrid. Static and dynamic tests have been carried out on this test bench. The first set of tests has been focused on the characterization of the structure formed by the main beam of the catenary and the supports that anchor it to the roof or voussoirs. These tests have made it possible to evaluate the deformation of the assembly under its own weight and to establish the best possible characterization of the joint between components. Main result obtained is related to the supports and their vertical stiffness against upward forces, allowing to simplify their action within the set to a linear force. The second set of tests, of a dynamic nature, are focused on evaluating the deformations of the main beam of the catenary under different force patterns. These tests have made it possible to identify the main resonance modes of the system, thus knowing the vibration frequencies at which the greatest displacements occur. The increase in the vertical displacement of the catenary beam translates into instabilities when maintaining contact between the pantograph and the catenary infrastructure, producing undesirable losses of contact and impacts. Globally considering the set of tests developed and the results obtained from them, the test scenario is reproduced in the form of virtual models both within the CAD software and in the Matlab tool that has been developed. The same tests that have been carried out on the ADIF facilities are reproduced on these models, so that a results comparison matrix can be created in accordance with what is shown in the following diagram. With this methodology, a parallel validation model is created allowing to evaluate the quality of the generated models against a real structure. The latest contribution and verification of the quality of the simulation methods developed has been possible thanks to the collaboration in research projects of the Polytechnic University of Madrid together with the Swiss Federal Railways. Latter organization has provided the project with exploitation data of an overhead contact rail section with a system configuration of the same characteristics as the one used as a reference located in ADIF facilities. Both the need to work within manageable time frames within the development period of the thesis and the quality of the results obtained with the self-developed simulation tool based on Matlab have conditioned the final research results. The main block of application tests carried out has been focused on the study of the maximum running speed at which the quality of the contact between pantograph and catenary can be preserved, considering as variables the distance between consecutive supports, the distance between consecutive pantographs and the type of pantograph. As a result, the following tables are obtained. First one is for the pantograph model described in EN 50318:2003 standard and the second for the WBL85 pantograph model. The quality of the results collected in these tables is evidenced by the fact that they have been considered for the maximum running speed recommendations included in IRS 70020 of the UIC. Once the behavior and dynamics of the current collection process are known, an extension of the tool focused on predictive maintenance has been developed. It has been possible to evaluate the wear profiles that may appear in the contact platens that are installed in the pantographs depending on the geometric characteristics of the catenary installation, including the characteristic offset of these systems. This extension has allowed the evaluation of different types of stagger and the effect they may have on lifecycle of components. The flexibility of the calculation tool developed, as well as the analyzes carried out on the dynamics of the overhead contact rail system, have allowed the stiffness compensators shown in this document to be developed and patented under reservation number ES2683778. The development of this system, focused on the management of the oscillations that occur in the main catenary beam, has been the result of the development of the idea of combining in the same electrical current distribution system the benefits provided by flexible catenary systems and rigid ones. By separating the main beam from the copper wire through an elastic device, the movement of the body with the greatest weight is isolated from the body in permanent contact with the pantograph, allowing a stable contact force throughout the displacement and improving useful life forecasts. As a whole, it has been possible to combine many knowledge sources and apply them in a practical way to the generation of simulation tools that have in turn allowed the development of operating patterns based on the infrastructure facilities.