Rotor optimization in a superconducting magnetic bearing by using frozen image model and Amperian current approximation

Developments in superconducting magnetic bearings led the key technological progresses for flywheel energy storage systems. However, the present status of the superconducting magnetic bearings still deprived from the sufficient stability. Since the magnetization characteristics of the superconducting materials reaches the limits the necessity of more efficient designs for bearing systems is inevitable. For instance, strongly stable bearing designs would be possible by using various magnetic and superconducting components in the bearing. In this context, we have investigated the effect of particular levitation configuration on the stability of the rotor in the bearing mechanism. Vertical and lateral forces acting on the rotor are determined in terms of the various shape and dimensions of the superconductors and permanent magnets. In this context, the Amperian current approximation was used to model the interaction force between the permanent magnets. In the case of determining the interaction force between the permanent magnet and high temperature superconductor, the frozen image model was used to implement the Amperian current approximation according to the cooling procedure of the superconductor. It was determined that the optimum levitation of the rotor strongly depends on the use of superconductor and permanent magnet configurations.