Faults current limitation in a Railway DC substation based on Superconducting technology

To meet the high transport demand in the urban areas, railway companies are required to increase train traffic and particularly the feeder power that supplies the trains. Increasing DC power leads to rising fault currents in the substations that can exceed 110 kA. The main purpose of this study is to limit fault current and optimise rectifier diode (I
²
t) in the DC substation for railway networks. This limitation will enable to reduce the oversize of the network components, to minimise their investment and maintenance costs. A resistive superconducting fault current limiter is used. First, the DC substation with and without faults current is modelled using EMPTP-RV software. A detailed model of the superconducting limiter based on REBCO tapes is then modelled using Matlab software. Results from REBCO models are integrated into the substation under faults conditions and then optimised to achieve the required limitation. A case study is carried out using the SNCF network in Paris. Results show 50% faults limitation and 23.75% I
²
t optimisation of rectifier diode in transient regime.