Dynamic interaction between multiple pantographs sliding on an overhead conductor wire: a multibody and wave-based approach

Abstract

he interaction dynamics between a number of railway pantographs moving in contact with an overhead high-tension conductor wire has been studied. The bases of the pantographs are subjected to harmonic excitation with different phases representing track undulation. The overhead wire is modelled as a viscoelastically supported infinite taut string, and a multibody model of the pantograph is proposed. Natural coordinates and extended Hamilton’s principle are used to derive the equations of motion of the multibody system, which are then linearised about its static equilibrium state for a small amplitude of base excitation. To follow the method of substructure synthesis in determining the responses of multiple pantographs with the help of the linearised models and subsequently in estimating the contact force, the dynamic stiffness matrix associated with the continuum is analytically calculated using the wave propagation approach. It is found that the separation distance between the pantographs, the travel speed and the base excitation phase have significant influences on the collective behaviour of the pantographs. Counter-intuitively, a leading pantograph may not always affect the trailing ones. The phase of the base excitation can actually play a decisive role, as brought out in this work.