Basic design and characteristics study of a double-axial superconducting magnetic bearing system

Under the background of upgrading energy crisis, a double-axial superconducting magnetic bearing (SMB) system was designed and fabricated for a flywheel energy storage system (FESS) model to demonstrate high temperature superconducting (HTS) energy-saving technologies. In order to levitate and stabilize the shaft sufficiently, the static levitation force and lateral force between high temperature superconductor (HTSC) stator and permanent magnet (PM) rotors in two different sizes were checked. Based on the stable levitation, the dynamic characteristics of the SMB system were also investigated by the excitation experiments. The running experiments show that in the case of a driving motor the shaft can stably rotate along the central axis without any contact, while intensified vibration is also observed near two resonance rotational speeds. These results have been applied to construct and operate the FESS model using the SMB system.