Dynamic stiffness of a railway overhead wire system and its effect on pantograph-catenary system dynamics

For an electrical railway overhead wire system there are two main factors w hich crucially affect the quality of current collection. One is the spatial stiffness variation of the overhead wire along each span and the other is the flexural wave motion in the wire. In this paper a periodically excited single-degree-of-freedom (SDOF) model of a combined pantograph-catenary sys tem is introduced and its basic dynamic behaviour is discussed. To investig ate the effect of wave propagation in the overhead wire on vibration of the pantograph the dynamic stiffness of the catenary is introduced into the mo del. The dynamic stiffness of the catenary is determined by representing th e overhead wire system as an infinite periodically spring-supported string. The results show that the dynamic stiffness of the catenary varies with tr ain speed and its effect on the performance of the pantograph-catenary syst em is discussed. (C) 1999 Academic Press.