Impact of Superconducting Cables on a DC Railway Network

Abstract

The Société Nationale des Chemins de fer Français (SNCF) is facing a significant challenge to meet the growth in rail traffic while maintaining continuous service, particularly in densely populated areas such as Paris. To tackle this challenge, the SNCF has implemented several electrification projects. These projects aim to reduce line losses and decrease voltage drops on the railway network. Amongst the possible technological choices, high temperature superconductor (HTS) cables have been evaluated, since they offer greater energy density at lower electrical losses than conventional cables. This feature is advantageous in order to transmit more electrical energy at a lesser footprint than conventional cable, therefore avoiding costly modifications of the existing infrastructures. In the present work, the electromagnetic response of two HTS cables topologies, unipolar and bipolar, was analyzed, and their impact on a direct current (DC) railway network under load was assessed. A commercial finite element (FE) software, COMSOL Multiphysics, was used to carry out a detailed FE model that accounts for the non-linearity of the electrical resistivity ρ (J, B, θ) of the superconducting cable. This FE model was coupled with a lumped-parameter circuit model of the railway network, which is particularly suited for transient simulations considering train motion. Based on a case study representing a portion of the Parisian railway network, it was found that the insertion of a superconducting cable can result in a reduction of electrical losses by 60% compared to conventional cable as well as an 8.6% reduction in the total electrical consumption of the traction network.

FEM-Circuit co-simulation of superconducting synchronous wind generators connected to a DC network using the homogenized J–A formulation of the Maxwell equations

“…Nevertheless, the co-simulation technique presents some challenges for modeling HTS devices. These challenges arise from the highly nonlinear and strongly multi-physical nature of the superconductor combined with the numerical complexity of dealing with distributed solvers; a specific FEM solver for simulating the machine and a distinct solver for the circuit simulator [27]. Both segregated solvers exchange variables over the course of the time-dependent analysis forcefully yielding an obvious issue of computation speed [28].…”

Synthesis and Research of Critical Parameters of Bi-HTSC Ceramics Based on Glass Phase Obtained by IR Heating

“…They are used in such fields as energy, electronics, etc. They are used to create motors and electric generators [1], power cables [2][3][4], current limiters for short circuits [5][6][7] and many others. It is known that the main parameters of superconductors are critical temperature (T c ), critical current (J c ) and critical magnetic field (H c ).…”