2018 年 26 巻 2 号 p. 413-418
This paper proposes a simple method to reduce amplitude of a magnet that levitates on a high temperature superconductor (HTS). The system works by a coil set above the magnet. The vibration of the magnet induces the current in the coil, and the current creates a magnetic field in such a direction that suppresses the vibration of the magnet. The coil is connected to an electric circuit consisting of a resistance and a capacitor, and works as an electromagnetic shunt damper which converts mechanical energy to electrical energy. The optimal parameters to achieve such a result are determined from the fixed point theory, and numerically analyzed in this paper.
