A non-linear simulation model of an active magnetic bearings supported rotor system

Nowadays active magnetic bearings (AMBs) are utilized in a wide range of applications including high-speed flywheel energy storage devices. This paper aims at reporting on the modeling and simulation of a flywheel energy storage system supported by AMBs. Firstly the non-linear AMB model is discussed that comprises the power amplifiers, displacement sensors, anti-aliasing filters and controller. The results of the non-linear AMB model are compared to conventional linear AMB models. Secondly the rotor model is discussed. The rotor model was implemented by means of the finite element method and the simulated results compared to a commercial rotor-dynamic software package. The rotor model is then integrated with the AMB models and the system is simulated under step disturbance inputs at the bearing positions as well as a run-up test to determine the unbalance response of the rotor.