0
research-article

Orbit response recognition during touchdowns by instantaneous frequency in active magnetic bearings

[+] Author and Article Information
Mindong Lyu

State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
lmd5936@sina.com

Tao Liu

State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
liutao0418@126.com

Zixi Wang

Associate Professor, State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
zxwang@mail.tsinghua.edu.cn

Shao-Ze Yan

Professor, State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
yansz@mail.tsinghua.edu.cn

Xiaohong Jia

Associate Professor, State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
jiaxh@mail.tsinghua.edu.cn

Yuming Wang

Professor, State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
yumingwang@tsinghua.edu.cn

1Corresponding author.

ASME doi:10.1115/1.4037850 History: Received November 30, 2016; Revised August 24, 2017

Abstract

During touchdowns of active magnetic bearings (AMB), the violent collision between rotors and touchdown bearings (TDB) can cause damages to both parts. Orbit response recognition provides a way for the AMB controller to automatically switch the control algorithm to actively suppress the rotor-TDB vibration and promptly re-levitate the rotor during touchdowns. A novel method based on Hilbert transform (HT) is proposed to recognize the orbit responses (pendulum vibration, combined rub and bouncing, and full rub) in touchdowns. In this method, the rotor suspension status is monitored by the AMB controller in real-time. When touchdown is detected, the rotor displacement signal during the sampling period is intercepted and the instantaneous frequency (IF) is calculated by HT. Then, the local variance of IF during the sampling period is calculated and it is compared with the threshold value. Combined rub and bouncing can be identified for it has the largest local variance. Finally, the mean value of IF during the sampling period is calculated and is compared with the other threshold value. Pendulum vibration can be identified for it has a lower and fixed mean value while full rub has a larger value. The principle of the recognition method is demonstrated by the simulate results of a thermo-dynamic model. The results reveal that the method is feasible in recognizing the orbit responses and can be implemented in the AMB controller to help switch the control algorithms automatically in case of touchdowns.

Copyright (c) 2017 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In