Magnetic bearings can be divided into the following three categories

According to the way of providing magnetic force, magnetic bearings can be divided into the following three categories:

(1) Active Magnetic Bearing (Active Magnetic Bearing for AMB), also known as Active Magnetic Bearing. The magnetic field is controllable. After detecting the position of the suspended rotor, the control system stops the active control to complete the suspension of the rotor;

(2) Passive magnetic bearing P (assiveMagnetioBearing referred to as PMB), also known as passive magnetic bearing, uses permanent magnets or superconductors to support the local freedom of the rotor;

(3) Hybrid magnetic bearing (permanent magnet bias) (HsharidMa, etieBearing referred to as HMB), its mechanical structure contains electromagnets and permanent magnets or superconductors.

The magnetic bearing uses the attraction between the electromagnet and the ferromagnetic material to complete the non-contact suspension of the rotor. If a constant excitation current passes through the electromagnet, the rotor is an unstable system, and a small disturbance can cause the rotor to deviate from the equilibrium position. Recovery, therefore, it is necessary to apply active control to the magnetic bearing to make the rotor work stably.