Abstract:The odd harmonic current of the magnetically suspended rotor system caused by the two major vibration sources of mass imbalance and sensor harmonics can lead to harmonic vibration, which seriously affects the pointing accuracy of the ultra-stable and ultra-static satellite platform. A second-order dual-mode odd repetitive controller based on particle swarm optimization is proposed to address the issue of rotor frequency perturbation, which improves frequency robustness and achieves high-precision and rapid suppression of odd harmonic components in magnetic bearing current. Firstly, a dynamic model of the magnetically suspended rotor system containing two vibration sources is established. Secondly, the structure design and harmonic suppression principle of the second-order dual-mode odd repetitive controller with weight factor and control gain are analyzed in detail, and the stability criterion is given. Then, according to the coupling relationship between weight factor and control gain in the stability criterion, the particle swarm optimization algorithm is used to intelligently select the optimal values of the three parameters. Finally, simulation verification was conducted in both time and frequency domains. The simulation results show that the proposed method can effectively improve the suppression accuracy and speed of harmonic currents under rotational frequency perturbation.