Analysis of Stray Magnetic Field of Superconducting Magnets inside Superconducting Electrodynamic Suspension Carriages

A three-dimensional electromagnetic simulation model of superconducting electrodynamic suspension on-board superconducting magnets, null-flux coils, propulsion coils, and carriage structure is established using finite element simulation. The stray magnetic field inside the carriage is analyzed exhaustively, and the magnetic field distribution in the interior space of the carriage is obtained. The results show that the maximum static magnetic field inside the carriages exceeds 30 mT and the peak low-frequency magnetic field is 6 mT. This is higher than the limit values suggested by the International Commission on Non-Ionizing Radiation Protection for static magnetic field (0.5 mT) and low-frequency (1-100 Hz) magnetic field (0.2 mT). This work can provide a reference value for the optimal design of magnetic shielding for superconducting electric magnetic levitation trains.