An Improved Control System for a Split Winding Bearingless Induction Motor

Different types of bearingless induction motors have been reported in the literature. One of them is the rotor cage induction motor with split windings. Continuing research about this theme, this paper proposes a new control system. Since the radial forces are consequences of magnetic energy changes, the modeling and the speed control of this system are implemented in the reference frame of the airgap magnetic flux. In addition, due to the lag between the stator current vector and the reference flux, an automatic correction of the angular orientation of the Cartesian coordinates of the position sensors is proposed. In a wide operation range, experimental results show the effectiveness of this approach.