Thesis (M.S., Electrical and Computer Engineering)--University of Idaho, June 2014 | High speed flywheel energy storage (FES) systems are predicted to outperform battery systems in terms of lifetime and energy density. With proper development FES systems could become the new standard in energy storage for space and terrestrial applications. Active magnetic bearings (AMBs) are an enabling technology for FES systems. Flywheel energy storage systems rely on AMBs to suspend the flywheel without physical contact and allow the flywheel to rotate freely at high speeds. Active magnetic bearings provide magnetic suspension forces which are adjusted in response to control feedback to remove incident disturbances on the suspended flywheel. This thesis describes the modeling, simulation, and control system design of two decentralized AMB systems utilized on an experimental FES system built at the University of Idaho. One AMB is a dedicated outer-rotor eight pole system. The other AMB system is integrated within a self-bearing field regulated reluctance machine.