Output Feedback Control of Pantograph-Catenary System

Abstract

Controlling the contact force between the pantograph and the catenary has become a requirement for improving the performances and efficiency of high-speed train systems. Indeed, these performances may considerably be reduced because of the catenary equivalent stiffness variation. In addition, the contact force may also vary and could become null, which may cause the loss of contact. Then, in this paper, we present an active control of the pantograph-catenary system. The proposed control strategy implements an output feedback control, using a common approximation of the catenary equivalent stiffness. Namely, the proposed solution is based on backstepping techniques and takes benefit from the exponential convergence of a high-gain observer. All the synthesis steps of the control law are given and a formal analysis of the closed loop stability shows an asymptotic tracking of a nominal constant contact force. Then, using a simulation example, the contact force results to be practically equal to the its constant reference, meaning that the effects of the catenary equivalent stiffness variation have been cancelled and showing the effectiveness of this solution.