Vibration Characteristics of the HTS Maglev Vehicle Running on a 45-m-Long Ring Test Line

With further studies of high-temperature superconducting (HTS) maglev in recent years, several countries have built short-distance test lines for proving the feasibility of HTS maglev in the long-term running status, and the scientific exploration gradually develops from stable levitation experiments to dynamic performance tests. In previous studies, the sufficient levitation and guidance forces have been verified, but they ignore the influence of external disturbances in practical operations such as inhomogeneous magnetic fields along the permanent-magnet guideway, which limits the operation speed and causes potential vibrations. Meanwhile, the overlarge vibration might reduce the comfort of passengers and bring bad stability of the vehicle. Hence, the research of the dynamic characteristics in the actual operation process is an important process of the HTS maglev system. This paper makes use of the latest research result of a 45-m-long HTS maglev ring test line to study the dynamic vibration characteristics of the maglev vehicle under different running conditions, including different velocities, loads, and sections of the ring test line. Experimental results show that the amplitude of vibration acceleration increases with the velocity of the vehicle. In the vertical direction, the vibration acceleration curves reflect favorable axis symmetry, which confirms an excellent self-stable characteristic of the HTS maglev system, whereas in the lateral direction, the vibration acceleration has different trends on straight and curve lines. The lateral vibration acceleration on the straight lines is always fluctuating around the equilibrium position, and it has a rising trend on curve sections caused by stronger centrifugal phenomenon. Moreover, a proper increase in the levitation load can weaken the vibration, particularly with an enhancing velocity. These results help us to have a deep insight into the potential of HTS maglev and make preparations for the following long-distance dynamic tests.