Superconducting Magnetic Energy Storage (SMES) for Urban Railway Transportation

Morden railway transportation usually requires high-quality power supplies to guarantee fast and safe operation. Renewable energy such as solar power and wind power, will be highly utilized in future transportation systems. However, renewable energy technologies have issues of instability and intermittence. An energy compensation scheme with superconducting magnetic energy storage (SMES) is introduced for solving these energy issues of railway transportation. A system model consisting of the 1.5 kV/1 kA traction power supply system and the 200 kJ SMES compensation circuit were established using MATLAB/Simulink. The case study showed that if a 50 ms voltage fluctuating fault was from 1.2 kV to 1.8 kV in a traction system, the SMES could rapidly response within 5 ms and stabilize the voltage at 1.5 kV. Overall, the proposed new SMES scheme can potentially achieve the voltage stabilization and energy compensation for urban railway transportation.