Active Magnetic Bearing System Using PID-surface Sliding Mode Control

This paper proposes PID-surface sliding mode control (SMC) method for controlling active magnetic bearing system (AMB). AMBs are the typical electromagnetic products, which provide stable suspension for rotors. AMBs are used in a wide range of applications such as energy storage, high-speed-turbine applications, blood pumps, mixers, etc. AMBs can levitate rotor without mechanical contact, friction and lubrication. The AMBs employed in this paper have two four-pole bearings, whose distances can be controlled by using the current signal from the controller. The magnetic forces are generated by feedback loop control. The designation of PID-surface SMC reduces the chattering phenomenon in conventional SMC. The simulation results prove the high quality of the proposed control approach.