Numerical Calculation And Experiment Of High Temperature Superconducting Magnetic Bearings

The applications of the high temperature superconductor (HTS) become promising due to development of the manufacturing process and improvement of superconducting properties.Because of the flux pinning properties of the HTSs,the superconductors can be levitated stably on the permanent magnets (PM) ,which are entirely passive and do not require any active control systems. The high temperature superconductors were applied to the magntic systems;for example, the high temperature superconducting magnetic bearings,as a kind of magnetic bearings,have the properties of no contact,no friction ,long life and simple structure etc.So the HTS magnetic bearing has been a subject of considerable interest for the last decade all over the world.First the structure and properties of magnetic bearings are depicted,and the development status and future application are introduced in the introduction.The most important parameters of the HST bearings were the levitation force and stiffness.Based on the critical state model and current vector potential,the electric current distribution were calculated by the finite element method(FEM),then the force and stiffness can be computed by the Lorentz formula.A convenient application software which can be used to calculate the force of HTS bearings was developed by author.The parameters which influenced the bearing system were researched by the software.The parameters include the dimensions of the PMs and HTSs,the critical current density and the positions.Results calculated by the software were compared with the experimental results, and the simulated results and experimental ones correspond to each other. Several HTS axial bearings which had different structures and dimensions were simulated by the software, and got the force and current distribution which can be the theoretic foundation of the design and optimize of the HTS bearings.