Suppression of vibration caused by residual unbalance of rotor for magnetically suspended flywheel

For a magnetically suspended flywheel (MSFW), the residual unbalance of rotor can cause synchronous vibration and reduce the attitude control precision of spacecrafts. To eliminate the vibration caused by the residual unbalance of rotor suspended by magnetic bearing, the theorem of unbalance vibration is researched, and it is pointed out that the vibration can be successfully suppressed through the elimination of synchronous component in magnetic suspension forces by a magnetic suspension force compensation method. Based on the general notch filter, this method is proposed to be closed-loop style when the rotor rotates beyond its critical stable speed and to be open-loop style when the speed of the rotor is less than the critical stable speed by additional displacement stiffness compensation segment, open and closed-loop control method. The stability of this method is analyzed and the ability to eliminate n octave synchronous is verified in the whole speed range of the rotor. Experimental results demonstrate that this method can suppress the unbalance vibration significantly in the operation speeds of MSFW and is suitable for MSFW in that the rotor traverses its critical stable speed frequently.