SuperRail: strengthening and securing power supply for railways

Upgrading and securing power supply of railway networks

In June 2022, Nexans, in collaboration with SNCF Réseau and with support from Bpifrance, embarked on an innovative project aimed at enhancing the power supply infrastructure at Montparnasse train station in Paris, France. The project responds to the increasing demands on the railway network, necessitating a robust and efficient electrical system to support the growing rail traffic in one of Europe’s busiest transportation hubs. Montparnasse station, established in 1840, ranks as France’s fourth-largest train station, serving over 50 million passengers annually with an expected surge to 90 million by 2030. The installation of superconducting cables aims to meet the escalating power demands imposed by this anticipated growth in rail traffic.

The project faces several significant challenges, foremost among them being the need to upgrade the power supply infrastructure while minimizing disruptions to ongoing rail and road operations. The unique solution to this challenge lies in the utilization of superconducting cables, which will be integrated into Montparnasse station’s existing conduits. This approach presents engineering complexities, as it requires precise coordination to install the new cables within the confines of the pre-existing infrastructure without disrupting the station’s operations. Additionally, ensuring compatibility between the superconducting cables and the existing conduits poses technical challenges that demand meticulous planning and execution.

Nexans solution

Nexans plays a pivotal role in the project, drawing on its experience in superconductor technology and electrical infrastructure. The Group was tasked with designing and manufacturing the superconducting cables, as well as coordinating their installation within the existing conduits at Montparnasse station. Only a superconducting cable can combine a reduced diameter and exceptional power to deliver the performance required by SNCF Réseau: 5.3 MW per conduit, or 3,500 A to 1,500 VDC.

Superconducting power cables offer unparalleled advantages. As they have zero resistance, they transport electricity with minimal power loss and thus contribute to making the world more sustainable. This project illustrates perfectly how their compact nature enables them to transport very high power through a limited space. A single superconducting cable can replace multiple copper cables. Also, it has a minimal footprint, making high-capacity 1,500 V connections possible, which in turn improves the safety of the stations’ power supply.

Two cables connecting the Vouillé substation to the overhead lines of the tracks serving Montparnasse were pulled in 2023. The main stages of this project are the design and manufacturing of the Nexans components in Bourg-en-Bresse, Calais and Hanover for a prototype loop (cable, joint, terminations) which were tested in the SNCF Réseau laboratory in Vitry-sur-Seine, followed by the manufacturing of the two cables and their installation in the existing conduits.

This superconducting cable is the result of Nexans’ innovation capabilities in the fields of electricity and global sustainable electrification – an approach that has been part of the company’s history and DNA for more than 120 years.