Research On Coupling Performance Between Pantograph And Catenary Parameters Based On Frequency Analysis

The electric energy of high-speed locomotive is collected by the pantograph-catenary system. With the increase of train speed, the dynamic characteristic of the pantograph-catenary system becomes a key factor restricting the upgrade of driving speed. In order to study the dynamic characteristic accurately, some methods have been developed, in which computer simulation method is the main way. The computer simulation method based on mathematical model is convenient and costs less, and can simulate a variety of situations. The models of pantograph and catenary are derived and modified respectively, the more accurate pantograph-catenary coupling dynamic model is established in this paper. Then the coupling performance between pantograph and catenary parameters based on frequency analysis is discussed. The main work and research results are as follows.(1) The Euler Bernoulli beam is selected to model catenary and the lumped pantograph model is adopted. The coupling dynamic model is established using penalty function method. The model is solved with the method of Newmark and is proved reliable via the comparison with EN50318. The air damping of catenary is developed renewably. The influence of factors of air damping are analyzed and the pantograph-catenary coupling dynamic model is modified considering air damping. The dynamic characteristics of the pantograph-catenary system with different wind speeds are studied.(2) The variation characteristics of high-speed railway contact force are analyzed. Then the amplitude-frequency characteristics of pantograph under the impact of contact force are derived. Combined with the analysis of force fluctuation, the coupling relation is obtained. Through adjusting the pantograph parameters to make the frequency of the minimum response in the amplitude-frequency curve be equal to the frequency of the droppers, the fluctuation in contact force would be lowered, which means that the current collection quality is improved to some extent. Then the variation of the amplitude-frequency characteristics is analyzed by changing pantograph parameters seperately. The effect of collector head’s mass and stiffness on the amplitude-frequency charateristics is obvious. Finally the coupling relationship is validated in the pantograph-catenary dynamic system by observing the fluctuation in contact force with different mass and stiffness of collector head respectively.(3) According to the linear characteristics of the lumped pantograph model, the pantograph framework model is derived. And the dynamic equivalent model is simplified at the equilibrium position. The characteristics of the equivalent model and the equivalent parameters are analyzed. Then the curve of equivalent parameters with the change of working heights is fitted. And the pantograph-catenary coupling dynamic model is modified considering the equivalent parameters. The dynamic characteristics of the modified pantograph-catenary system affected by the nonlinear characteristics of pantograph under different speed are studied. The results demonstrate as follows:the fluctuation in contact force is more stable by considering the nonlinear characteristics of the pantograph. In the higher speed, the influence becomes more obvious. Finally the coupling performance between pantograph parameters and dropper frequency is validated in the modified pantograph-catenary dynamic model.