Mass-losses relationship in an optimized 8-pole radial AMB for Long Term Flywheel Energy Storage

This paper presents the effect of losses on a radial active magnetic bearings (AMB), used in the long term flywheel energy storage (LTFES). The study does not take into account the losses due to power electronics and windage losses (due to the friction between external rotor surface and the air). Therefore, we restricted the loss computation to those of radial AMB only. To simplify this work, we focused on the effect of external disturbance on unbalance force induced by rotor eccentricity for instance. The unbalance force has fixed the maximum radial load capacity of the rotor in order to design the radial AMB. 2-D finite element method (FEM) has been used to validate the theoretical model. We have optimized AMB system in order to search the best design which minimises overall losses (Copper and iron Losses) for different magnitudes of external force. Then, mass versus losses curve of AMB has been shown for the same angular velocity speed of rotor namely 9000 rpm.