Self-sensing estimates the air gap within an electro
magnetic path by analyzing the bearing coil current and/or voltage
waveform. The self-sensing concept presented in this paper has been
developed within the research project “Active Magnetic Bearings
with Supreme Reliability" and is used for position sensor fault
detection.
Within this new concept gap calculation is carried out by an alldigital
analysis of the digitized coil current and voltage waveform.
For analysis those time periods within the PWM period are used,
which give the best results. Additionally, the concept allows the
digital compensation of nonlinearities, for example magnetic
saturation, without degrading signal quality. This increases the
accuracy and robustness of the air gap estimation and additionally
reduces phase delays.
Beneath an overview about the developed concept first
measurement results are presented which show the potential of this
all-digital self-sensing concept.
[1] R. Gurumoorthy,W. L. Soong, J. P. Lyons, and A. F. Storace.
Implementation of sensorless control of radial magnetic bearings. in
Proc. MAG -95 - Magnetic Bearings, Magnetic Drives and Dry Gas
Seals Conference & Exhibition, pages 239-248, Alexandria, Virginia,
August 10-11 1995.
[2] B. V. Jayawant, B. E. Dawson, R. J. Whorlow, and J. C. Peyton Jones.
Digitally controlled transducerless magnetic suspension system. in IEE
Proceedings of Science, Measurement and Technology, volume 143,
pages 47 - 51, January 1996.
[3] L. Kucera. Robustness of self-sensing magnetic bearing. in Proc.
Magnetic Bearings Industrial Conf., pages 261 - 270, Alexandria, VA,
1997.
[4] Lichuan Li, T. Shinshi, and A. Shimokohbe. State feedback control for
active magnetic bearings based on current change rate alone. IEEE
Transactions on Magnetics, 40(6):3512 - 3517, November 2004.
[5] D. Montie. Performance Limitations and Self-Sensing Magnetic
Bearings. PhD-thesis, University of Virginia. January 2003.
[6] M.D. Noh and E.H. Maslen. Self-sensing magnetic bearings using
parameter estimation. IEEE Transactions on Instrumentation and
Measurement, 46(1):45 - 50, February 1997.
[7] Y. Okada, K. Matsuda, and B. Nagai. Sensorless magnetic levitation
control by measuring the PWM carrier frequency component. in Proc.
3rd Int. Symp. on Magnetic Bearings, pages 176-183, Alexandria,
Virginia, July 29-31 1992.
[8] A. Schammass, R. Herzog, P. Buehler, and H. Bleuler. New results for
self-sensing active magnetic bearings using modulation approach. IEEE
Transactions on Control Systems Technology, 13(4):509 - 516, July
2005.
[9] A. Schulz, M. Neumann, J. Wassermann, A Sophisticated Active
Magnetic Bearing System with Supreme Reliability, in Proc. 11th Int.
Symp. on Magnetic Bearings, Nara, Japan, Aug. 26-29 2008.
[10] A. Schulz, A. Gamez Sangra M. Neumann, J. Wassermann, Modelling
and simulation of a sophisticated active magnetic bearing system, in
Proc. X. Int. Conf. Theory of Machines and Mechanisms, IFToMM,
Liberec, Czech Repub., Sep. 2-4 2008
[11] A. Schulz, M. Neumann, J. Wassermann, A Sophisticated Concept for
Supreme AMB Reliability, in Proc. 9th International Conference on
Motion and Vibration Control - Movic 2008, Munich, Germany, Sep.
15-18 2008.
[12] A. Schulz, M. Neumann, J. Wassermann, Modeling and Simulation of a
Hot-Swap Controller Amplifier Module for an Active Magnetic Bearing
with Supreme Reliability, in Proc. 9th International Conference on
Modeling and Simulation of Electric Machines, Converters and Systems
- Electrimacs 2008, Quebec, Can., Jun. 8-11.
[13] A. Schulz, Simulation eines ausfallsicheren aktiven Magnetlagers, in
Proc. Schwingungen in rotierenden Maschinen - SIRM 2009, Vienna,
Austria, February 23-25 2009.
[14] A. Schulz, A hot-swap controller amplifier module for active magnetic
bearings with supreme reliability - electronic circuitry and error
detection strategies, in Proc. 20th International Symposium on Power
Electronics, Electrical Drives, Automation and Motion - Speedam 2010,
Pisa, Italy, June 14-16 2010.
[15] A. Schulz, An All-Digital Self-Sensing Concept, IEEE Transactions on
Magnetics, (not published - in preparation)
[16] G. Schweizer, E.H. Maslen, Magnetic Bearings: Theory, Design, and
Application to Rotating Machinery, Berlin Heidelberg: Springer-Verlag,
2009.
[17] P. Tsao, S.R. Sanders, and G. Risk. A self-sensing homopolar magnetic
bearing: analysis and experimental results. in Proc. Industry Applications
Conference, volume 4, pages 2560 - 2565, October 3 - 7 1999.
[18] D. Vischer. Sensorlose und spannungsgesteuerte Magnetlager. PhD
thesis, Eidgenössische Technische Hochschule (ETH) Zurich,
Switzerland, 1988.
[1] R. Gurumoorthy,W. L. Soong, J. P. Lyons, and A. F. Storace.
Implementation of sensorless control of radial magnetic bearings. in
Proc. MAG -95 - Magnetic Bearings, Magnetic Drives and Dry Gas
Seals Conference & Exhibition, pages 239-248, Alexandria, Virginia,
August 10-11 1995.
[2] B. V. Jayawant, B. E. Dawson, R. J. Whorlow, and J. C. Peyton Jones.
Digitally controlled transducerless magnetic suspension system. in IEE
Proceedings of Science, Measurement and Technology, volume 143,
pages 47 - 51, January 1996.
[3] L. Kucera. Robustness of self-sensing magnetic bearing. in Proc.
Magnetic Bearings Industrial Conf., pages 261 - 270, Alexandria, VA,
1997.
[4] Lichuan Li, T. Shinshi, and A. Shimokohbe. State feedback control for
active magnetic bearings based on current change rate alone. IEEE
Transactions on Magnetics, 40(6):3512 - 3517, November 2004.
[5] D. Montie. Performance Limitations and Self-Sensing Magnetic
Bearings. PhD-thesis, University of Virginia. January 2003.
[6] M.D. Noh and E.H. Maslen. Self-sensing magnetic bearings using
parameter estimation. IEEE Transactions on Instrumentation and
Measurement, 46(1):45 - 50, February 1997.
[7] Y. Okada, K. Matsuda, and B. Nagai. Sensorless magnetic levitation
control by measuring the PWM carrier frequency component. in Proc.
3rd Int. Symp. on Magnetic Bearings, pages 176-183, Alexandria,
Virginia, July 29-31 1992.
[8] A. Schammass, R. Herzog, P. Buehler, and H. Bleuler. New results for
self-sensing active magnetic bearings using modulation approach. IEEE
Transactions on Control Systems Technology, 13(4):509 - 516, July
2005.
[9] A. Schulz, M. Neumann, J. Wassermann, A Sophisticated Active
Magnetic Bearing System with Supreme Reliability, in Proc. 11th Int.
Symp. on Magnetic Bearings, Nara, Japan, Aug. 26-29 2008.
[10] A. Schulz, A. Gamez Sangra M. Neumann, J. Wassermann, Modelling
and simulation of a sophisticated active magnetic bearing system, in
Proc. X. Int. Conf. Theory of Machines and Mechanisms, IFToMM,
Liberec, Czech Repub., Sep. 2-4 2008
[11] A. Schulz, M. Neumann, J. Wassermann, A Sophisticated Concept for
Supreme AMB Reliability, in Proc. 9th International Conference on
Motion and Vibration Control - Movic 2008, Munich, Germany, Sep.
15-18 2008.
[12] A. Schulz, M. Neumann, J. Wassermann, Modeling and Simulation of a
Hot-Swap Controller Amplifier Module for an Active Magnetic Bearing
with Supreme Reliability, in Proc. 9th International Conference on
Modeling and Simulation of Electric Machines, Converters and Systems
- Electrimacs 2008, Quebec, Can., Jun. 8-11.
[13] A. Schulz, Simulation eines ausfallsicheren aktiven Magnetlagers, in
Proc. Schwingungen in rotierenden Maschinen - SIRM 2009, Vienna,
Austria, February 23-25 2009.
[14] A. Schulz, A hot-swap controller amplifier module for active magnetic
bearings with supreme reliability - electronic circuitry and error
detection strategies, in Proc. 20th International Symposium on Power
Electronics, Electrical Drives, Automation and Motion - Speedam 2010,
Pisa, Italy, June 14-16 2010.
[15] A. Schulz, An All-Digital Self-Sensing Concept, IEEE Transactions on
Magnetics, (not published - in preparation)
[16] G. Schweizer, E.H. Maslen, Magnetic Bearings: Theory, Design, and
Application to Rotating Machinery, Berlin Heidelberg: Springer-Verlag,
2009.
[17] P. Tsao, S.R. Sanders, and G. Risk. A self-sensing homopolar magnetic
bearing: analysis and experimental results. in Proc. Industry Applications
Conference, volume 4, pages 2560 - 2565, October 3 - 7 1999.
[18] D. Vischer. Sensorlose und spannungsgesteuerte Magnetlager. PhD
thesis, Eidgenössische Technische Hochschule (ETH) Zurich,
Switzerland, 1988.
@article{"International Journal of Mechanical, Industrial and Aerospace Sciences:50944", author = "Alexander Schulz and Ingrid Rottensteiner and Manfred Neumann and Michael Wehse and Johann Wassermann", title = "Self-Sensing versus Reference Air Gaps", abstract = "Self-sensing estimates the air gap within an electro
magnetic path by analyzing the bearing coil current and/or voltage
waveform. The self-sensing concept presented in this paper has been
developed within the research project “Active Magnetic Bearings
with Supreme Reliability" and is used for position sensor fault
detection.
Within this new concept gap calculation is carried out by an alldigital
analysis of the digitized coil current and voltage waveform.
For analysis those time periods within the PWM period are used,
which give the best results. Additionally, the concept allows the
digital compensation of nonlinearities, for example magnetic
saturation, without degrading signal quality. This increases the
accuracy and robustness of the air gap estimation and additionally
reduces phase delays.
Beneath an overview about the developed concept first
measurement results are presented which show the potential of this
all-digital self-sensing concept.", keywords = "digital signal analysis, active magnetic bearing,
reliability, fault detection.", volume = "4", number = "11", pages = "1175-8", }