Running characteristics of the superconducting magnetically levitated train in the case of superconducting coil quenching

A superconducting(SC) magnetically levitated (Maglev) transportation system has been developed in Japan and various experiments have been done in the new test line at Yamanashi prefecture. Although the superconducting electrodynamic suspension (EDS) system has the advantage of stable levitation without active control, various electromagnetic or mechanical disturbances can cause the change of gap length and the displacement or oscillation of the bogie. In this system, the severest disturbance is SC coil quenching. Therefore it is important to show the running characteristics of the Maglev train and to increase the stability in this case. We developed three dimensional numerical simulation program for the Maglev train. Using this program, running simulation of the train for Yamanashi new test track was undertaken in the case of SC coil quenching. Because of the damping characteristics of the EDS system, influence of the coil quenching is smaller at a higher speed. In the train model, electromagnetic spring strength of the EDS system is larger than mechanical spring of the secondary suspension system connecting a bogie and cabins. Therefore influence of the quenching is only seen in the cabins connected to the quenched bogie. Demagnetization of the SC coil quenching is considered to increase the stability of the train. Although this method is useful to decrease large guidance force, lateral displacement, yaw and roll angle of the bogie, vertical displacement and pitch angle become large.