Fuzzy Bang-Bang Relay Control of a Rigid Rotor Supported by Active Magnetic Bearings

Active magnetic bearings, which are open-loop and unstable, require a feedback control system to ensure stable operation of the rotating machines that they support. Proportional-integral-derivative (PID) controllers widely used in field applications these bearings for this purpose. PID designed work effectively within linear region machines. Due inherent nonlinearity active large unbalance forces may occur result nonlinear vibration responses. Therefore, controller’s effectiveness is considerably reduced when become large. Other strategies, such as fuzzy logic sliding mode schemes, more apt deal with responses supported by bearings. The present proposes an integrated bang-bang relay controller rigid rotor mounted on suppress vibrations examined numerically. Performance comparison conventional PD made different initial conditions, imbalance magnitudes, angular speeds. At extreme operating conditions due forces, where highly nonlinear, proposed proved be superior over controllers.