Recently, magnetic bearings with non-contact levitation have been researched to overcome the deficiencies of the mechanical ball bearings. An active magnetic bearing (AMB) works on the principle of electromagnetic levitation and consists of many electromagnets, power amplifiers, controllers, and gap sensors with associated electronics to provide the feedback required to control the position of the rotor within the gap. This paper deals with a four-pole active magnetic bearing control using sliding mode controller with saturation function to reduce chattering phenomenon of controlled current. After the introduction of basic structure and mathematical model of the 4-pole active magnetic bearing, the paper focus on analyzing the implementation of designing sliding mode control with signum function and saturation function. Finally, a simuation of the four-pole active magnetic bearing based on Matlab/Simulink is developed in order to confirm the proposed control method. The simulated results show that the magnetic bearing can work stably in all radial directions and the control system with saturation strongy reduce chattering phenomenon.
Keyword
Active Magnetic Bearing, Sliding Mode Control, Saturation Function
