Développement de câbles supraconducteurs pour la transition énergétique

Keywords

Superconductor, Cryogenic, Electrical Engineering

Subject details

The increase in rail traffic, in conjunction with the growing demand for sustainable mobility, is giving rise to a number of new energy challenges. The provision of uninterrupted rail services, particularly within densely populated urban areas, necessitates the development of innovative electrification solutions. In this particular context, the use of high-temperature superconducting (HTS) cables is a technology that shows great promise, with the capability of carrying power without experiencing any loss or voltage drop. This doctoral project, overseen by the GREEN laboratory, is in alignment with the overarching objective of reducing carbon emissions in the rail sector and, by extension, power grids in general. The objective of this research is to enhance the overall efficiency of superconducting cables, with a particular focus on addressing the technical challenge posed by terminations. Terminations serve to establish the connection between the ambient temperature and the cryogenic environment of the cable. These terminations, which can be extensive and unwieldy, impede the integration of these cables into embedded systems and also have a detrimental effect on overall system efficiency. Superconducting cables appear to be a viable solution for a number of applications, particularly in the field of aeronautics. Nevertheless, a number of scientific and technical bottlenecks persist. It is evident that the terminations which establish the connection between the ambient temperature and the cryogenic environment of the cable represent a domain that is susceptible to enhancement and optimization. Presently, these components of the cable constitute a length of approximately one meter, a factor that can render their integration challenging, or even unfeasible, particularly in embedded applications. The objectives of the present PhD project are therefore twofold: firstly, to optimize the superconducting cable system, with a focus on the terminations and their associated cooling system; and secondly, to achieve a comprehensive understanding of the relevant scientific principles. The original approach is to adopt a pragmatic stance on the solutions to be implemented, and to study and model the termination from an electrical and thermal perspective, integrating various heat exchangers and cooling systems. It is imperative that the entire system is optimized for a range of several thousand amperes. The project adopts a pragmatic and interdisciplinary approach, combining electrical engineering, thermal management, cryogenics, and fluid mechanics. The research plan includes • A state-of-the-art review (month 3), • The design of a test bench to evaluate different configurations (month 9), • A comparative study of several termination solutions (month 12), • The development of a 5 kA termination prototype (month 24), • Followed by the final manuscript writing (month 30). The expected outcomes are numerous: improved integration of superconducting cables in constrained environments (such as rail and aeronautics), reduced use of strategic raw materials like copper and aluminum, and a significant contribution to CO₂ emissions reduction.