Modeling and Stabilization of a Novel Flywheel Energy Storage System

This thesis is about a novel design of a flywheel storage system with magnetic bearing. The system employs magnetic coupling technology to directly transmit power. The proposed design results in minimal energy loss. If power is transmitted indirectly via electromagnetic induction, the energy transfer efficiency would be lower. The motor rotor and flywheel share the same rotor shaft, which is supported by two sets of five-degree-of-freedom magnetic bearings. Since the bearings are non-contact, the flywheel's rotational speed can be increased, thereby enhancing the stored energy. The heat sources for the drive and the magnetic bearings are located outside the flywheel's vacuum chamber, facilitating heat dissipation without affecting the flywheel. Additionally, integral sliding mode control (ISMC) has been incorporated. According to simulation results, the system will remain stably suspended at the equilibrium position.