Estimation and Rejection of Unknown Sinusoidal Disturbances Using a Generalized Adaptive Forced Balancing Method

Harmonic disturbance attenuation in a three-pole active magnetic bearing test rig using a modified notch filter

“…Despite the effectiveness, this method produces large reaction forces and coil currents which cause vibration and noise in the foundation and power loss in the coils, especially in high rotational speeds. In the second approach, an adaptive signal is generated to minimize the harmonic amplitudes of the coil currents (Herzog et al, 1996;Na and Park, 1997;Vahedforough et al, 2007). The reaction forces are eliminated with this method, but small harmonic amplitudes will remain in rotor displacements.…”

Compensation and Control of Bearingless Induction Motor’s Unbalanced Exciting Force Based on LMS Filter

“…Motor with magnetic bearings has been widely used in high-speed drive kingdoms [3][4][5], but it has a series of disadvantages, such as: higher magnetic suspensions cost, difficulty to over speed, [6][7][8]. Based on the comparability of stator structure between magnetic bearing and conventional AC motor, the bearingless motor is proposed [9][10][11][12].…”

“…About the unbalance vibration problem of magnetic bearing motor, a variety of control methods are proposed, such as notch filter, adaptive feedforward and feedback compensation, robust control, and sliding mode control [3][4][5][6][7][8]. But, about the unbalance vibration control of bearingless motor, research literatures are very rare, the existing researchs are limited to bearingless synchronous motor, and mainly concentrated in the compensation method of unbalanced displacement, and the compensation purpose is to force the rotor to rotate around its inertial axis [13][14][15], and then, still cannot meet the requirements of suspension control precision in some application fields, such as high speed grinder drive field.…”

Stability analysis and imbalance compensation for active magnetic bearing with gyroscopic effects

“…Additionally, it is structurally stable, and parameter variations in the controlled object are independent [15]. Compared with methods of fuzzy control [11], nonlinear decoupled disturbance observer [12], adaptive forced balancing [13], Furrier coefficient identification [14], generalized notch filter [16], the adaptive notch filter can reduce the computation effort or memory space [17], especial suitable for the MSCMG with a rotor at constant speed and many control tasks. This paper is arranged as follows.…”

“…Imbalance compensation has received a great attention [11]- [16], the imbalance compensation approaches fall into three categories, which are the clean displacement approach [11]- [13], the clean current approach [13]- [15], and the clean force approach [14]- [16]. The clean displacement approach can minimize the shaft displacement vibration through an added bearing stiffness with a high level of position precision, but it comes at the expense of high vibration force, whereas the clean force approach minimizes the vibration force but leads to a large vibration displacement, which endangers the system stability.…”