scholarly journals Control of Magnetic Bearing System

10.5772/51185 ◽  
2012 ◽  
Author(s):  
Hwang Hun ◽  
So Nam ◽  
Joo Ho
Keyword(s):  
Magnetic Bearing ◽  
Bearing System

scholarly journals Nonlinear Behavior of a Magnetic Bearing System

1995 ◽  
Vol 117 (3) ◽  
pp. 582-588 ◽  
Author(s):  
L. N. Virgin ◽  
T. F. Walsh ◽  
J. D. Knight
Keyword(s):  
Degrees Of Freedom ◽  
Initial Conditions ◽  
Nonlinear Behavior ◽  
Analytical Techniques ◽  
Magnetic Bearing ◽  
Forced Response ◽  
The Mathematical Model ◽  
Two Degree Of Freedom ◽  
Sensitivity To Initial Conditions ◽  
Bearing System

This paper describes the results of a study into the dynamic behavior of a magnetic bearing system. The research focuses attention on the influence of nonlinearities on the forced response of a two-degree-of-freedom rotating mass suspended by magnetic bearings and subject to rotating unbalance and feedback control. Geometric coupling between the degrees of freedom leads to a pair of nonlinear ordinary differential equations, which are then solved using both numerical simulation and approximate analytical techniques. The system exhibits a variety of interesting and somewhat unexpected phenomena including various amplitude driven bifurcational events, sensitivity to initial conditions, and the complete loss of stability associated with the escape from the potential well in which the system can be thought to be oscillating. An approximate criterion to avoid this last possibility is developed based on concepts of limiting the response of the system. The present paper may be considered as an extension to an earlier study by the same authors, which described the practical context of the work, free vibration, control aspects, and derivation of the mathematical model.

scholarly journals Digital Linear Control System for a Magnetic Bearing System of a High Vacuum Turbomolecular Pump

2010 ◽  
Vol 19 (4) ◽  
pp. 256-264
Author(s):  
Seung-Kook Ro ◽  
Jin-Ho Kyung ◽  
Jong-Kweon Park ◽  
Woo-Ho Nam ◽  
Deug-Yong Koh
Keyword(s):  
Control System ◽  
High Vacuum ◽  
Magnetic Bearing ◽  
Linear Control System ◽  
Linear Control ◽  
Turbomolecular Pump ◽  
Bearing System

Multi-State Transient Rotor Vibration Control Using Sampled Harmonics

2002 ◽  
Vol 124 (2) ◽  
pp. 186-197 ◽  
Author(s):  
P. S. Keogh ◽  
M. O. T. Cole ◽  
C. R. Burrows
Keyword(s):  
Magnetic Bearing ◽  
Measured Data ◽  
Rapid Decrease ◽  
Flexible Rotor ◽  
Rotor Vibration ◽  
Transient Vibration ◽  
Stability Boundaries ◽  
Vibration Attenuation ◽  
Harmonic Components ◽  
Bearing System

A technique is introduced to achieve transient vibration attenuation in a multi-input, multi-output flexible rotor/magnetic bearing system. The strategy employs feedback control of measured harmonic components of rotor vibration. Whereas previous harmonic controllers have been based only on steady state vibration characteristics, the new controller also incorporates the transient dynamics. The controller may still be designed from measured data and is determined from target transient vibrational responses arising from step changes in particular disturbances. Account is taken of delays arising from evaluation of harmonic components. Furthermore, stability boundaries for the controller are shown to have significant tolerance to measurement error. The controller is validated experimentally in a flexible rotor/magnetic bearing system and mass loss tests are used to demonstrate rapid decrease in vibration levels with near elimination of transient overshoot.

Sign in / Sign up

Export Citation Format

Share Document