Control of Magnetic Bearings with plug-in time-varying harmonic resonators

A common problem in the operation of rotors is the sinusoidal disturbance caused by mass unbalance. Mass unbalance manifests as a harmonic force with frequency synchronous to the rotor speed. In a rotor-bearing system using Active Magnetic Bearings (AMBs), this issue is especially important as the gap between the rotor and electromagnets is small and rotor unbalance may cause the rotor to make contact with the housing. In this paper, an adaptive resonator is implemented in a plug-in architecture to keep the rotor in stable levitation for varying rotor speeds while reducing the affects of rotor unbalance.