Electrodynamic Magnetic Bearings for Flywheel Energy Storage System

Flywheel energy storage system (FESS) is one of the most appealing energy storage technologies due to its longer lifetime, higher efficiency, higher power density and superior charging and discharging cycle. However, as a result of friction and losses in its mechanical bearings, the utilization of FESS is limited to short-term application such as load levelling and frequency regulation for wind power smoothing. This paper investigates an alternative magnetic bearing technology to be used in tandem with FESS. Five electrodynamic magnetic bearing variants are presented. The stiffness and stability of the proposed bearing are solved using 3D finite element analysis. The proposed bearings are aimed to control the radial degree of freedom of FESS.