Combined FIR and Fractional-Order Repetitive Control for Harmonic Current Suppression of Magnetically Suspended Rotor System

• Published in: IEEE transactions on industrial electronics (1982) Vol. 64; no. 6; pp. 4828 - 4835
• Main Authors: Cui, Peiling, Wang, Qirui, Li, Sheng, Gao, Qian
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.06.2017; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Active control; Delays; Finite impulse response filters; FIR filters; Harmonic analysis; Harmonic current; Impulse response; Low-pass filters; Magnetic bearings; Magnetic levitation; magnetically suspended rotor; mass unbalance; Military helicopters; Performance degradation; Power harmonic filters; Repetitive control; repetitive control (RC); Resonant frequencies; Rotors; sensor runout; Unbalance; Vibration control
• ISSN: 0278-0046; 1557-9948
• DOI: 10.1109/TIE.2017.2668985

Magnetically suspended rotor has the characteristics of no friction and active vibration control. The mass unbalance and sensor runout of the rotor induce harmonic current, which will cause harmonic vibration. The ratio of the sampling rate to the fundamental frequency of harmonic current is often not an integer. The existing repetitive control (RC) for the suppression of harmonic current in magnetic bearing is applicable for the integer case. Harmonic current suppression performance is degraded drastically if the ratio is fractional. In this paper, combined finite-impulse response (FIR) and fractional-order RC is proposed. FIR filter and fractional-order RC are combined to perform harmonic current suppression at arbitrary frequency. Phase compensator is designed to enhance the stability of magnetically suspended rotor system. Experimental results are given to verify the effectiveness and superiority of the proposed method.