Electromagnetic force and eddy current loss in dynamic behavior of a superconducting magnetically levitated vehicle

A magnetically levitated vehicle is being designed to travel between Tokyo and Osaka in about 1 h at a 500-km/h speed. When the car runs at a high speed, it moves laterally and vertically from its balanced position at low frequencies. The authors present calculations of electromagnetic forces and eddy currents generated in the onboard cryostat containing the superconducting magnet as a result of these motions. They show that the electromagnetic forces, eddy current losses and damping constants of the motion, especially for the lateral and vertical motions, depend on the materials of the radiation shield and the inner vessel in the magnet and change with the frequencies of car motion. The magnitudes of forces, losses, and damping constants in lateral motion are compared with those in vertical motion. To evaluate these quantities, numerical calculations were performed with a two-dimensional finite-element method.<>