Servo Actuated Railway Pantograph for High-Speed Running with Constant Contact Force

Abstract

High-speed running on the Italian railway has been recently developed. One of the main problems to be solved for good high-speed running is the current pick-up with a pantograph from an overhead contact line. This problem can be solved by biasing, at very high values, the stiffness of the springs acting on pantograph arms. Unfortunately, in this way the pantographs developed up to now, based on previous experience, gave bad results due to excessive contact force (that is, after 2000 km it is necessary to change the worn contact shoe). A simple approach to easily and quickly solve this problem is the use of a servo actuated pantograph able to maintain the contact force at a given value. In this way the main problem to be solved is the right choice of the force actuator kind. Starting from the existing pantograph the authors show how it should be possible to have an almost constant contact force using an optimized servo actuated pantograph.