Compensation of Disturbances on Self-Sensing Magnetic Bearings Caused by Saturation and Coordinate Coupling

Self-sensing is a posibility to simplify active magnetic bearing systems. In this paper a method to determine the rotor position in magnetic bearings by measuring the clock-frequent components of the coil current and voltage generated by pulse width modulated amplifiers is discussed. Ways are pointed out to overcome the problems resulting from the ambiguity of the identification signals due to the non-linearities of the magnets as well as to avoid the distortions of the identification signals due to magnetic coupling between the individual magnets.