End effect on magnetic damping force of superconducting inductive magnetic levitation system

Abstract

The magnetic damping force for the vertical motion of superconducting inductive levitation system is analyzed. The ground coil current induced by the vertical motion of vehicular coil generally takes a maximum value after the first vehicular coil has passed over the ground coil. At 500 km/h, for instance, this current takes the maximum value around when the second vehicular coil is passing over the ground coil. Hence, the damping force exerted on the first vehicular coil is positive and that exerted on the second vehicular coil is negative. Since the latter is larger than the former, the resultant damping force becomes negative. The influence of the end effect on the magnetic damping force means that a positive damping force is exerted on the first vehicular coil and a negative damping force with larger strength is exerted on the second vehicular coil. This end effect vanishes almost completely in the low-speed region when the third and subsequent vehicular coils pass over the ground coil. In the high-speed region, however, it lasts for a comparatively long time.