Enhancement of the stability of maglev sled based on the secondary suspension system

In the field of high-speed ground propulsion, the electrodynamic suspension system of the maglev sled using null-flux coils demonstrates considerable application potential due to its advantages such as high load capacity and high lift-to-drag ratio. However, this system often exhibits poor stability owing to insufficient vertical damping. This study proposes adding a secondary suspension system to the sled to improve ride stability by introducing an elastic buffer layer between the car body and the bogie frame. First, a field-circuit-motion coupled model is established, and its stability is analyzed. Subsequently, the secondary suspension system is introduced, and its dynamic model is developed. Using track random irregularities as the excitation and the ride stability index as the optimization criterion, the particle swarm optimization algorithm is employed to optimize the structural parameters. To reduce the impact on sled acceleration, the feasibility of employing the secondary suspension system with various car body masses is examined, and the vibration suppression performance under track beam vertical misalignment is also analyzed. The results indicate that this approach can effectively suppress vertical vibrations, thereby enhancing ride stability. This study provides a useful reference for the design of suspension systems for high-speed maglev sleds.