Thermal stability of maglev SCMs with vibration-induced disturbances

Abstract

Abstract In magnetic levitation (Maglev) systems, the interaction between the superconducting magnets (SCMs) and the discrete ground coils causes electromagnetic and mechanical vibrations. These disturbances can limit the performance of the Maglev. We examine how the electromagnetic oscillations are translated into mechanical vibrations and the subsequent effects on thermal stability. Dynamic circuit theory is used to determine the harmonic forces on the SCM. The vibrational response of the SCM to these forces is analyzed via normal mode calculations. The energy dissipation within the conductor due to hysteresis damping is then determined, forming the input to a two-dimensional thermal stability analysis. This paper focuses on the extension of the thermal stability model from one to two dimensions and results obtained from modeling the performance of MLU002. Results of this analysis show how variations in mechanical properties of the conductor affect the stability of MLU002 as a function of velocity. It was found that vibrational resonance occurs at certain combinations of Young's modulus and vehicle velocity, quenching the magnets. The ability to predict the velocity at which resonances occur allows future Maglev designs to avoid such quenches by shifting the critical velocity above that intended for operation.