Suppression of Harmonic Vibration in Active Magnetic Bearing Rotor System With Finite-Dimensional Synchronous Rotating Frame Transformation

In an active magnetic bearing (AMB) rotor system, harmonic vibration caused by rotor mass imbalance and sensor runout is the main disturbance. To suppress these disturbances, a harmonic vibration suppression method based on finite-dimensional synchronous rotating frame transformation (FSRFT) is proposed. The FSRFT is constructed to suppress the harmonic currents by using the orthogonal output signals from the radial <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">X</i> and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Y</i> displacement sensors. It maintains the stability of the system by adjusting the phase compensation angle at different speeds. On this basis, a displacement stiffness feed-forward compensation is constructed to realize the synchronous displacement stiffness force compensation and achieve the suppression of harmonic vibration force. Simulations and experiments verified the effectiveness of the proposed method, which can suppress the harmonic currents and further compensate for the synchronous displacement stiffness force to reduce the harmonic vibration on the AMB-rotor system.