چكيده به لاتين
Abstract
Dynamic interaction of the overhead catenary system and pantographs is one of the most critical barriers of increasing speed in highspeed trains. Also, conventional trains are affected by inappropriate contact quality because the problem in contact quality leads to not only increase maintenance cost but also damage in catenary as the infrastructure. In order to avoid either sparking or contact loss, the uplift force should be high enough and form the other hand, less mechanical wear can be achieved via low uplift force. Therefore, there is an optimum level for the uplift force. By studying the dynamic characteristics of pantograph and catenary, the optimum values of stiffness and damping of pantographs components can be calculated in order to reduce oscillation of contact force and to keep it around the optimal value. In this study, after reviewing the current available finite element/volume model, a novel nonlinear (time-varying) analytical model has been developed for the interaction of pantograph and catenary. This model has a good precision for calculating the static form of the catenary (by considering the weight of components and dead loads of droppers). Furthermore, the analytical model of the contact wire can simulate wave propagation and reflection. The model is able to linearize the system at any moment and design optimal state space controller. By lying to the mentioned model, the behavior of propagated wave in simple beam and complete catenary has been studied, and critical speed and wave speed have been compared. In order to improve the accuracy of results, the self-damping of messenger cable has been measured in the laboratory by a novel approach, and the model has been updated. The droppers cannot bear any compression load and they have non-linear behavior. In this study, the nonlinear behavior of droppers has been described by breaking running time to time steps between slacking time and re-tensioning time. The reference model of EN 50318 has been considered, and according to the instruction of this standard, the model has been validated. Furthermore, the simulation result of developed software has been compared with measured arcs of Tabriz-Jolfa and appropriate compatibility has been observed. The magnetic control force near the contact point is the main innovation of this study in controllers. The sensitivity of the designed controller has been analyzed via noise in controller current and environmental noise on contact wire (like wind-induced vibration). The controller has been applied to the contact wire with two different control strategy, minimizing contact force oscillation and minimizing vertical velocity of overlap point. Beside the magnetic controller, the overlap controller and pantograph controller has been considered and compared (therefore, 6 cases has been considered). The results show that the magnetic controller has the highest performanc and it can make significant enhance in contact qulity without changing the initial uplift force.
