Development of a hybrid simulation method for current collection systems, using a real-time multi degree-of-freedom catenary model

Abstract

This paper provides a hybrid simulation (HS) system for pantograph/catenary systems based upon the dynamically substructured system (DSS) method. HS consists of a physical pantograph, an actuator to excite the pantograph head and a real-time simulator for the catenary model. The real-time simulator calculates the displacement of the contact wire using the contact force between the pantograph head and the actuator. Since the actuator is driven by the calculated displacement of the contact wire at the contact point of pantograph and contact wire, HS provides a pseudo dynamical testing method for pantograph/catenary systems. In this paper a multi degree-of-freedom (MDOF) catenary model is adopted, in order to realise wave propagation of the vertical displacement along the wires. To compensate for the dynamic characteristics of the actuator, the DSS method is adopted, which uses both state feedback and output feedback control. A key finding in this work is that the DSS-based HS system is more accurate than the commonly-used inverse transfer function method. Furthermore, in order to realise real-time simulation of the MDOF catenary model, this study uses a modal analysis technique to reduce the dimension of the catenary model. Additionally, the long catenary model is reduced to a 4-span model, and, by copying the state of the wires and contact point, long distance travelling of the pantograph is realised. The proposed method has been validated by simulated HS testing and by HS testing using an actual pantograph at the Railway Technical Research Institute.