Active Magnetic Bearings Stiffness and Damping Identification from Frequency Characteristics of Control System

At present, the stiffness and damping identification for active magnetic bearings (AMBs) are still in the stage of theoretical analysis. The theoretical analysis indicates that if the mechanical structure and system parameters are determined, AMBs stiffness and damping are only related to frequency characteristic of control system, ignoring operating condition. More importantly, few verification methods are proposed. Considering the shortcomings of the theoretical identification, this paper obtains these coefficients from the experiment by using the magnetic bearing as a sine exciter. The identification results show that AMBs stiffness and damping have a great relationship with the control system and rotating speed. Specifically, at low rotating speed, the stiffness and damping can be obtained from the rotor static suspension by adding the same excitation frequency. However, at high speed, different from the static suspension situation, the AMBs supporting coefficients are not only related to the frequency characteristics of control system, but also related to the system operating conditions.

[1]  Neil Genzlinger.  A. and Q , 2006 .

[2]  Paul E. Allaire,et al.  Digital control of active magnetic bearings , 1990 .

[3]  Luis San Andrés,et al.  Field Methods for Identification of Bearing Support Parameters—Part II: Identification From Rotor Dynamic Response due to Imbalances , 2007 .

[4]  Qintao Guo,et al.  Active Magnetic Bearing Rotor Model Updating Using Resonance and MAC Error , 2015 .

[5]  Luis San Andrés,et al.  Field Methods for Identification of Bearng Support Parameters—Part I: Identification From Transient Rotor Dynamic Response due to Impacts , 2007 .

[6]  Ni Zuo-xi.  Identification method for stiffness and damping of magnetic bearings based on rotor unbalance responses , 2013 .

[7]  WU Xin-yue.  Application of boundary element method to measuring dynamic stiffness and damping of bearing , 2008 .

[8]  M. Friswell,et al.  IDENTIFICATION OF SPEED-DEPENDENT BEARING PARAMETERS , 2002 .

[9]  Dongsheng Zhang,et al.  Design and parameter estimation of hybrid magnetic bearings for blood pump applications , 2009 .

[10]  Nan-Chyuan Tsai,et al.  Identification of rod dynamics under influence of Active Magnetic Bearing , 2011 .

[11]  Paul E. Allaire,et al.  Effect of Control Algorithms on Magnetic Journal Bearing Properties , 1986 .

[12]  Zhao Hongbin.  Study on stiffness and damping characteristic of active magnetic bearing , 1999 .

[13]  Xiping Wang,et al.  Analysis on stiffness and damping performance of active magnetic bearing system , 1998 .

[14]  Rajiv Tiwari,et al.  Identification of the Bearing and Unbalance Parameters from Rundown Data of Rotors , 2011 .

[15]  Luis San Andrés,et al.  Field Methods for Identification of Bearing Support Parameters: Part I — Identification From Transient Rotor Dynamic Response Due to Impacts , 2003 .

[16]  Rajiv Tiwari.  Conditioning of regression matrices for simultaneous estimation of the residual unbalance and bearing dynamic parameters , 2005 .

[17]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.