Design and FEM analysis of a flywheel energy storage system assisted by integrated magnetic bearings

This paper presents a compact and novel flywheel energy storage system. The flywheel acts as the rotor of the drive system and is sandwiched between two disk type stators. Concepts of magnetic levitation and axial-flux PM synchronous machine are incorporated to assist the rotor-flywheel to spin and remain in magnetic suspension in the gravitational axis. Three-dimensional finite element method is applied for studying the flux linkage, induced voltage, levitation force and rotational torque of the system. The analysis results support the feasibility of the proposed system.