Integration Design of High-Temperature Superconducting Bearing and Electromagnetic Thrust Bearing for Flywheel Energy Storage System

A structure design of hybrid magnetic bearing (HMB), which integrates radial type superconducting magnetic bearing (SMB) with axial type active electromagnetic bearing (AMB), was proposed to sustain the flywheel rotor of the superconducting flywheel energy storage system. The levitation force was simulated using the multi-physical field analysis software Comsol. Under the condition of definite outer-diameter of outer ring and inner-diameter of inner ring of the stator parameters, the optimal structure parameters of the electromagnetic bearing were designed with the goal of maximum magnetic force using the finite element software Ansys Maxwell. And the influence of key performance parameters between the SMB and AMB were also analyzed. The prototype was developed, the measurement experiments were conducted and the advantages were compared with other schemes. The results show that making use of SMB’s self-stabilization, the change rate of HMB levitation force with air-gap increase and the response rate of the AMB controller can be reduced; the heat of AMB coils can be effectively dissipated by taking liquid nitrogen as cooling medium; the integration structure design can improve the levitation force-to-volume ratio. And the effectiveness is validated. © 2019, Electrical Technology Press Co. Ltd. All right reserved.