Vibration Characteristics of Superconducting Magnets of Magnetically Levitated Vehicles. 1st Report. A Method of Decreasing the Vibration of the Inner Vessel and the Heat Load of the SCM.

Abstract

Superconducting magnets (SCM) for Maglev Vehicles are vibrated by several mechanical and electro-magnetic disturbances. The main disturbance is the vibration caused by the magnetic field fluctuation, which arises from the ground coils. Heat load and vibration characteristics under these conditions have been evaluated by electro-magnetic disturbance tests to simulate the actual running condition. Through the electro-magnetic disturbance tests with an initial type SCM which was made in 1990 on an experimental basis, it became clear that the heat load was more than several 10 W under a specific frequency, which exceeded the cryogenic refrigeration capacity. The heat load is increased at the same frequency by the increase of the acceleration of the inner vessel. From the results of the experiments and vibration analysis, it became clear that increasing the stiffness of the outer vessel decreases the amplitude of vibration of inner vessel. The heat load decreases for the amplitude reduction of the inner vessel vibration.