Dynamically substructured testing of railway pantograph/catenary systems

Abstract

This paper presents a methodology for testing railway pantograph/catenary systems based upon the dynamically substructured system (DSS) approach for combined physical and numerical components, originally developed by Stoten and Hyde. The main advantage of DSS is that it can provide more stable substructured testing than alternative schemes, such as the commonly used hybrid simulation method, often referred to as hardware-in-the-loop simulation. The developed method is validated through experiments using a simple pantograph rig, together with a numerical simulation of the catenary. In order to realise a real-time simulation of the large catenary model, for the first time in DSS testing this study uses (I) a modal analysis technique to reduce the dimension of the contact wire model and (II) a moving window approach to represent long-distance travel of the pantograph. Finally, the experimental DSS test results are compared with simulations of the benchmark pantograph/catenary emulated system.

New methods for dynamically substructured system testing of a railway car pantograph

“…These gains are chosen so as to transform the first derivative of equation (4) into a scalar homogeneous differential equation (see the Appendix) for stability analysis. The LSC gains K N 1( i -1) , K N 1( i +1) , K N 2( i ) and K P are determined as 16 where AN1(i,i) is i -th row and i -th column element of the normalAN1. It can be shown (see the Appendix) that the error dynamics are determined from equations (1)-(9) as the scalar homogeneous differential equation.…”

“…The DSS testing method has already been validated in the ACTLab, University of Bristol, via a simple mechanical rig exhibiting representative motion of a pantograph. 16…”

“…The DSS testing method has already been validated in the ACTLab, University of Bristol, via a simple mechanical rig exhibiting representative motion of a pantograph. 16 Also described in this study is the application and implementation of the DSS testing method to a shinkansen pantograph via two different methods of actuation: (I) a single-axis servohydraulic actuator supported by a rigid frame structure and (II) an actuated rotational disc, rotating in the horizontal plane, which represents the motion of the contact wire when in contact with the real pantograph. Schematic images of the two rigs are shown in Figure 2.…”

On the use of experimental modal analysis for system identification of a railway pantograph

“…An actuator is placed so that it excites the pantograph vertically at the top of the collector strip, slightly to the side of the middle. Two types of simulation methods use an actuator in the same position directly for their combined simulation method: the hybrid-in-loop method [12,15,16] and dynamically substructured (DSS) testing [17]. Several stepped sine sweep excitations are performed between 5 and 200 Hz.…”

Geometry deviation effects of railway catenaries on pantograph–catenary interaction: a case study in Norwegian Railway System

“…Another state of the art is to digitalise the external disturbance from vehicletrack [12,13], wind load [14] and other experimental factors and adequately include them in the numerical model. In order to improve the numerical efficiency, some scholars have devoted their attention to developing fast simulation techniques, such as the moving mesh [15], moving window [16] and offline integration method [17]. Commonly, the numerical models are used in the design phase to check the acceptance of the design strategy.…”