Damping Strategies on a Horizontal Rotor Supported by Electrodynamic Bearings

Electrodynamic Bearings (EDBs) exploit Lorentz type of magnetic force due to the eddy currents induced in a rotating conductor, which has relative motion in a magnetic field, to levitate the rotor. The character of passive levitation without negative stiffness that can be realized using permanent magnets in room temperature with relatively simple configuration makes EDBs an appealing alternative to Active Magnetic Bearings (AMBs). However, the instability of rotors supported by EDBs is the key issue that prevents the application of EDBs. In this paper, the damping strategies for EDB systems are investigated using additional AMBs implemented. The hybrid bearing system has been built to stabilize EDB system using damping from AMBs which work as Active Magnetic Dampers (AMDs). It can be further exploited to investigate the damping strategies with active control of the AMBs. The results are presented in this paper showing different possible solutions of EDB stabilization.