Dynamic levitation behavior of a radial-type SMB under axial load condition

Due to the external disturbances or the time-variable load, it is necessary to study the dynamic levitation behavior in order to guarantee the stable levitation of superconducting magnetic bearing (SMB). This paper investigates the dynamic levitation behaviors of a radial-type SMB under axial load condition. By adopting the Power-law EJ relation, the simplified H-formulation finite element model of a radial-type SMB was established to calculate the axial dynamic levitation behavior with the aid of the PDE module and ODE module in software COMSOL. The experimental measurements of the axial levitation force were performed in the field cooling condition so as to validate the model. Then, the dynamic levitation behaviors of the radial-type SMB were discussed when the PM rotor suffers from the external disturbances including the axial constant load with different initial velocities and the sinusoidal time-variable loads. The results show that both the load size and the initial velocity drift the work point of PM rotor. And the sinusoidal load leads to a complex time-evolution of the levitation behavior. The study is useful to predict the effects of external disturbances on the dynamic levitation behaviors in the practical applications of the SMB.