Hardware-in-the-Loop pantograph tests with general overhead contact line geometry

Hardware-in-the-loop testing serves as a method to examine the dynamic interaction between the pantograph and catenary within controlled laboratory environments. This task involves measuring the force from the pantograph, using a real-time catenary model to determine the next pantograph position, and generating the desired pantograph movement to complete the loop. To address potential instability issues arising from communication delays and the inherent stiffness in the interaction with pantograph strips, a mass–spring system and a Linear Quadratic Gaussian controller are integrated into the system. The catenary is a finite element model of a complete section, incorporating the non-linearity introduced by dropper slackening. Validation of the results demonstrates a good level of accuracy in the HiL test approach within the frequency range of 0–20 Hz.