Gain-scheduled control of a magnetic bearing with low bias flux

2002 ◽  
Author(s):  
C. Knospe ◽  
C. Yang
Keyword(s):  
Magnetic Bearing ◽  
Gain Scheduled

Application of gain scheduled H/sub ∞/ robust controllers to a magnetic bearing

1996 ◽  
Vol 4 (5) ◽  
pp. 484-493 ◽  
Author(s):  
F. Matsumura ◽  
T. Namerikawa ◽  
K. Hagiwara ◽  
M. Fujita
Keyword(s):  
Magnetic Bearing ◽  
Robust Controllers ◽  
Gain Scheduled

Analysis and Testing of a Magnetic Bearing Energy Storage Flywheel With Gain-Scheduled, MIMO Control

2000 ◽  
Author(s):  
Lawrence A. Hawkins ◽  
Brian T. Murphy ◽  
John Kajs
Keyword(s):  
Energy Storage ◽  
Dynamic Test ◽  
Magnetic Bearing ◽  
System Stability ◽  
University Of Texas ◽  
Mimo Control ◽  
Cross Axis ◽  
Five Axis ◽  
Gain Scheduled ◽  
Bearing System

The design and initial testing of a five axis magnetic bearing system in an energy storage flywheel is presented. The flywheel is under development at the University of Texas Center for Electromechanics (UT-CEM) for application in a transit bus. The bearing system for the prototype features homopolar permanent magnet bias magnetic bearings. The system has been successfully tested to the maximum design speed of 42,000 rpm. A gain-scheduled, MIMO control algorithm was required to control the system modes affected by rotor gyroscopics. The implementation and basis for this control scheme is discussed. The cross-axis forces produced by this approach are described in terms of circumferential cross-coupled stiffness and damping to explain the effect on system stability. Dynamic test results are discussed relative to the rotordynamic and control system design.

Aerodynamic Loading and Magnetic Bearing Controller Robustness Using a Gain-Scheduled Kalman Filter

1996 ◽  
Vol 118 (4) ◽  
pp. 836-842 ◽  
Author(s):  
R. D. Smith ◽  
W. F. Weldon ◽  
A. E. Traver
Keyword(s):  
Kalman Filter ◽  
Magnetic Bearing ◽  
Active Magnetic Bearings ◽  
Nonlinear Controller ◽  
Luenberger Observer ◽  
Aerodynamic Loading ◽  
Loading Effects ◽  
Critical Components ◽  
System Variables ◽  
Gain Scheduled

Modeling or predicting aerodynamic loading effects on rotating equipment has been a source of concern to those who wish to examine stability or response of critical components. The rotordynamic model of the system employed for such examination assumes greater importance for active bearings than for passive ones, if only because of the additional potential for instability introduced by the controller. For many systems, aerodynamic loading may vary widely over the range of operation of the bearings, and may depend on extended system variables. Thus, potential controllers for active magnetic bearings require sufficient robustness or adaptation to changes in critical aerodynamic loading parameters, as might be embodied in cross-coupled stiffness terms for compressor impellers. Furthermore, the presence of plant or measurement noise provides additional sources of complication. Here, the previous development of a nonlinear controller for a hypothetical single-stage centrifugal gas compressor is extended by comparing the compensator performance using a multivariable Luenberger observer against that of a stationary Kalman filter, both gain-scheduled for rotational speed. For the postulated system, it was found that the slower poles of the Kalman filter did not observably detract from controller convergence and stability, while predictably smoothing out the simulated sensor noise.

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