Safety-relevant release function for pantograph based electrified trucks and semi-trailers

In order to achieve the decarbonization of heavy-duty vehicles on the road, different electrification strategies are being investigated. One approach is to equip a fully electric truck with a pantograph to operate the electric motor via an overhead catenary line (OCL) on designated routes and to charge the vehicle's internal battery during the drive. This approach can theoretically provide the long-haul vehicle with an infinite range, only geographically limited by the availability of the OCL. The pilot projects are currently being tested on public roads in countries like Germany and Sweden, whereas countries like India, France, the UK and China have expressed interest in the technology. Pantograph-based, electric drive concepts are classically used in trams, trolley buses and railway operations. However, when to be used without the guide rails, changed conditions lead to different requirements and a simple transfer of technology is not possible. Therefore, the application requires significant development work. Part of these changed requirements are the conditions of actuation and the safety management of the pantograph during operation. Due to unpredictable drive maneuvers of various traffic participants, as well as boundary conditions given by the road traffic regulatory body, extended safety functions are necessary. Main aspect of this is the monitoring of safe operation through a release process. This includes a driver release coupled with a release function on the vehicle control side, which monitors specific measurement data for compliance with the defined limiting values. It leads to a semi-automated and redundant release process, that ensures the safe functionality of the pantograph for all events that occur during operation. This paper introduces and classifies the concept of a release function and defines the actuation conditions of the pantograph system. In addition, implementation details and challenges are addressed to provide a comprehensive overview. The results were derived from a research project currently being undertaken at the Chair of Production Engineering of E-Mobility Components at the RWTH Aachen University and is supported by the German Federal Ministry for Economic Affairs and Climate Action.