Nonlinear Vibration Suppression of HTS Maglev Utilizing Electromagnetic Shunt Damper

High temperature superconducting (HTS) bulks can realize self-stabilizing magnetic levitation (maglev) over permanent magnets (PM) due to their inherent flux pinning effect, has considerable potential for high speed transportation. However, when subjected to excitation, the maglev system may vibrate violently because of the weak damping characteristic. When the excitation amplitude and frequency meet certain conditions, periodic bifurcation and subharmonic resonance may occur, which is unwanted in maglev systems. Hence, based on the above situation, to enhance the damping characteristic of HTS maglev system, an electromagnetic shunt damper (EMSD) was applied to the HTS maglev system. The purpose of this paper is to investigate whether this EMSD can suppress the nonlinear vibration. Firstly, the dynamic equations of the maglev system and an EMSD was established. And then, numerical calculations of the forced vibrations were carried out via the Rung-Kutta method. Eventually, the results show that the EMSD can greatly suppress the vibration amplitude. The subharmonic resonance and the period-double bifurcation was not observed in the simulations with the addition of EMSD.