Dynamic characterization of permanent magnet electrodynamic suspension system with a novel passive damping magnet scheme

Abstract

In the paper, a 3D electromagnetic force analytical model incorporating the vertical vibration velocity of the permanent magnet is derived using the virtual magnetic charge method, which is used to examine the system’s dynamic properties. Then, a novel passive damping scheme based on permanent magnets is developed to enhance the system stability without increasing the complexity of the system. Finally, the dynamic experiment is carried out on the rotating platform employing a dynamic test apparatus, where the validity of the analytical model is checked and the effect of the damping magnet is explored. The results exhibit that the permanent magnet electrodynamic suspension system is self-stabilizing yet underdamped, and the vertical damping coefficient decreases as the velocity and airgap increase. The system has favorable stability in the absence of disturbance with a fluctuation of roughly 0.5 mm. The proposed damping scheme reduces the vibration overshoot from 41.18% to 32.47% and shortens the settling time from 3.29 s to 0.97 s. Meanwhile, the system is especially sensitive to long-wave irregularities in the high-speed range throughout the experiment with the track irregularity, where the vibration amplitude of the guidance system can be reduced by approximately 8 times from 4.6 mm to 0.57 mm by applying the damping magnet scheme. As a result, the proposed passive damping magnet scheme offers a pretty damping effect, which is capable of significantly improving the stability of the permanent magnet electrodynamic suspension system.