... is that it manages two significant physical quantities, namely, tangential and radial velocities, associated with steady-state and transient behaviors, respectively. Three controllers are compared for the control of a flexible rotor supported by active magnetic bearings (AMBs): proportional-integral-derivative (PID...

... occur across a small radial clearance in one transverse plane. A single radial active magnetic bearing is used to apply control forces in a separate transverse plane. The experiments confirm the conditions under which static feedback of the measured interaction force can prevent degenerate whirl...

... representations of the compression system dynamics are compared with the measured response of the experimental setup. Employing active magnetic bearings to perturb the axial impeller tip clearance of the compressor, the compression system is excited over a wide frequency range and the input-output response from...

... frequency ω H are experimentally identified. Also, the servo dynamics of the magnetic bearing that controls the axial impeller position is determined experimentally. To further validate the mathematical model and the feasibility of using the impeller tip clearance for controlling surge, we present a design...

...Hongchang Wang; Shuyun Jiang; Zupei Shen Active magnetic bearings and superconducting magnetic bearings were used on a high-speed flywheel energy storage system; however, their wide industrial acceptance is still a challenging task because of the complexity in designing the elaborate active control...

...M. Kamel; H. S. Bauomy The rotor-active magnetic bearing system subjected to a periodically time-varying stiffness having quadratic and cubic nonlinearities is studied and solved. The multiple time scale technique is applied to solve the nonlinear differential equations governing the system up...

...Tsuyoshi Inoue; Yukio Ishida; Takeshi Tsumura This study focuses on the vibration of the rotor supported by a repulsive-type passive magnetic bearing. It evaluates the restoring force of a repulsive magnetic bearing numerically by considering the effects of magnetic anisotropies of the inner...

... in ensuring a stable operating range to the rotor is studied by means of root loci. Comparison with literature results is finally used to validate the model. 07 02 2008 12 07 2008 15 10 2008 damping electromagnetic induction machine bearings magnetic bearings rotors stability...

... be applied by magnetic bearings to reduce the effective synchronous forcing which is driving the contact, so that the rotor can progress to a contact free orbit. It is shown that even in the presence of highly nonlinear contact dynamic effects, a linear finite element rotor model can be used to calculate...

...Robert J. Prins; Mary E. F. Kasarda; Samantha C. Bates Prins Locating the effective rotor origin of an active magnetic bearing (AMB) is an important step toward accurate characterization of the bearing air gaps for field tuning, performance analyses, and some shaft force measurement techniques...

...Naohiko Takahashi; Hiroyuki Fujiwara; Osami Matsushita; Makoto Ito; Yasuo Fukushima In active magnetic bearing (AMB) systems, stability is the most important factor for reliable operation. Rotor positions in radial direction are regulated by four-axis control in AMB, i.e., a radial system...

...Y. A. Amer; M. H. Eissa; U. H. Hegazy; A. S. Sabbah The dynamical behavior of a parametrically excited simple rigid disk-rotor supported by active magnetic bearings (AMB) is investigated, without gyroscopic effects. The principal parametric resonance case is considered and studied. The motion...

... rotor system incorporating two radial magnetic bearings, with standard proportional-integral-derivative control employed in a parallel feedback loop for rotor levitation. An experimental investigation of controller performance is used to deduce the best choice of wavelet basis for various operating...

...Guoxin Li; Zongli Lin; Paul E. Allaire; Jihao Luo This paper reports on the modeling and experimental identification of a high speed rotor-magnetic bearing test rig. An accurate nominal model and an uncertainty representation are developed for robust controller synthesis and analysis. A combination...

...J. C. Ji; Colin H. Hansen This paper is concerned with a study of the influence of a time delay occurring in a PD feedback control on the dynamic stability of a rotor suspended by magnetic bearings. In the presence of geometric coordinate coupling and time delay, the equations of motion governing...

...Y. S. Ho; H. Liu; L. Yu This paper is concerned with the effect of a thrust active magnetic bearing (TAMB) on the stability and bifurcation of an active magnetic bearing rotor system (AMBRS). The shaft is flexible and modeled by using the finite element method that can take the effects of inertia...

...Uhn Joo Na, Research Engineer; Alan B. Palazzolo, Professor; Andrew Provenza This paper provides a new algorithm and test verification for implementing fault-tolerant operation of magnetically suspended, flexible shaft, rotating machinery. The currents to the magnetic bearing are redistributed...

... and Sound for publication in the JOURNAL OF VIBRATION AND ACOUSTICS . Manuscript received May 2001; revised March 2002. Associate Editor: G. Flowers. 01 May 2001 01 March 2002 12 06 2002 resonance magnetic bearings machine bearings rotors chaos nonlinear dynamical systems...

...Uhn Joo Na, Research Associate; Alan Palazzolo, Professor Flux coupling in heteropolar magnetic bearings permits remaining active coils to assume actions of failed coils to produce force resultants identical to the un-failed actuator. This fault-tolerant control usually reduces load capacity...