Finite Element Analysis Of The Superconducting Magnetic Bearing Levitation Force

A high temperature superconducting magnetic bearing, constructed by high temperature superconductors and permanent magnetic material, is a new kind of bearing, which is untouched between it's stators and rotors. Since it is a stable system and doesn't need controllers, so the high-temperature superconducting magnetic bearing is used in some rotating machinery.Based on the electromagnetic field theory and the critical state model of high-temperature superconductor material, an analysis system for the high-temperature superconducting bearings using VB language on commercial FEM soft ANSYS, is developed in this paper. The static characteristics of the high temperature superconducting bearing are analysed and the flux density vector, magnetic field intensity and levitation force are obtained. The effect of bearing's type and bearing's structure parameters on the characteristics of the high temperature superconducting bearings is discussed.Levitation force is a function of distance between permanent magnet and superconductor, which is related with the bearing's construction. For a thrust superconducting magnetic bearing, the levitation force is the largest when permanent magnet's diameter or width approximates superconductor's diameter. For a radial superconducting magnetic bearing, axial levitation force is correlative to superconductor's axial displacement and radial levitation force is correlative to the radial displacement between the stator and the rotator. Results show that at the same distance between permanent magnet and superconductor, the levitation force is larger when the permanent magnet is approaching to superconductor than that when the permanent magnet is leaving superconductor.