Hybrid Magnetic Bearing Regulation via Super Twisting Control

A homopolar permanent magnet-biased magnetic bearing is a suitable solution to reduce power losses in active magnetic bearing systems. This configuration is complex due to the coupling between the coil-created magnetic fluxes and permanent magnet fluxes, besides being inherently a nonlinear, unstable, and multivariable system. One of the most recent topics in variable structure theory is represented by the higher order sliding modes (HOSM). In this paper, we propose the application of super twisting controller (STC) for the double loop robust stabilization of a rigid rotor horizontally supported by radial hybrid magnetic bearings. The efficiency of the applied controller is demonstrated via simulations in the presence of harmonic disturbances like vibration forces.