A hybrid-type superconducting magnetic bearing system with nonlinear control

In this paper, a hybrid-type superconducting magnetic bearing (SMB) system with nonlinear control is discussed. The hybrid-type SMB system consists of passive-type SMBs, active-type magnetic bearings (AMBs), a rotor, and sensors. The rotor position is controlled by nonlinear controller with no-bias currents. Because the controller does not need bias currents applied to the electromagnets, the energy losses are considered to be less than other magnetic bearing systems. The displacements of the rotor are suppressed by both the SMBs and the AMBs. The superconductors of the SMBs were field-cooled. Compliance for the bearings, displacements of the rotating rotor, and energy losses for the system were investigated. The results show that the hybrid-type SMB system with nonlinear control has good performances in these evaluations.