The fault-tolerant control scheme utilizes grouping of currents to reduce the required number of controller outputs. Reduced current distribution matrices can be calculated with the constraint conditions of the controller outputs and the necessary condition for linearization. Decoupling chokes are not required for the control scheme with grouped currents since fluxes are isolated in C-cores. By reducing controller outputs and removing decoupling chokes the fault-tolerant control scheme is more efficient and practical in terms of industrial applications.

Issue Section:
Technical Papers
Keywords:
magnetic bearings, fault tolerance, digital control, matrix algebra, control system synthesis, position control, voltage control, electric current control
Topics:
Bearings, Control equipment, Magnetic bearings, Currents, Poles (Building), Control systems, Fault tolerance
1.
Habermann, H., and Liard, G., 1979, “Practical Magnetic Bearings,” IEEE Spectr., IEESAM Sept., pp. 26–30.
2.
Allaire
,
P. E.
,
Lewis
,
D. W.
, and
Knight
,
J. D.
,
1983
, “
Active Vibration Control of a Single Mass Rotor on Flexible Supports
,”
J. Franklin Inst.
,
315
, pp.
211
–
222
.
3.
Salm, J., and Schweitzer, G., 1984, “Modeling and Control of a Flexible Rotor with Magnetic Bearing,” Proceedings of the Third International Conference on Vibrations in Rotating Machinery, pp. 553–561.
4.
Matsumura
,
F.
, and
Yoshimoto
,
T.
,
1986
, “
System Modeling and Control of a Horizontal-Shaft Magnetic-Bearing System
,”
IEEE Trans. Magn.
,
22
, pp.
197
–
206
.
5.
Maslen
,
E. H.
, and
Meeker
,
D. C.
,
1995
, “
Fault Tolerance of Magnetic Bearings by Generalized Bias Current Linearization
,”
IEEE Trans. Magn.
,
31
, No.
3
, pp.
2304
–
2314
.
6.
Meeker, D. C., 1996, “Optimal Solutions to the Inverse Problem in Quadratic Magnetic Actuators,” Ph.D. dissertation, Univ. of Virginia, Mechanical Engineering.
7.
Maslen
,
E. H.
,
Sortore
,
C. K.
,
Gillies
,
G. T.
,
Williams
,
R. D.
,
Fedigan
,
S. J.
, and
Aimone
,
R. J.
,
1999
, “
Fault Tolerant Magnetic Bearings
,”
ASME J. Eng. Gas Turbines Power
,
121
, pp.
504
–
508
.
8.
Lyons, J. P., Preston, M. A., Gurumoorthy, R., and Szczesny, P. M., 1994, “Design and Control of a Fault-Tolerant Active Magnetic Bearing System for Aircraft Engine,” Proceedings of the Fourth International Symposium on Magnetic Bearings, ETH Zurich, pp. 449–454.
9.
Maslen
,
E.
,
Hermann
,
P.
,
Scott
,
M.
, and
Humphris
,
R. R.
,
1989
, “
Practical Limits to the Performance of Magnetic Bearings: Peak Force, Slew Rate, and Displacement Sensitivity
,”
ASME J. Tribol.
,
111
, pp.
331
–
336
.
10.
Knight
,
J. D.
,
Xia
,
E.
,
McCaul
,
E.
, and
Hacker
, Jr.,
H.
,
1992
, “
Determination of Forces in a Magnetic Bearing Actuator: Numerical Computation With Comparison to Experiment
,”
ASME J. Tribol.
,
114
, pp.
796
–
801
.
11.
Allaire
,
P. E.
,
Fittro
,
R. L.
,
Maslen
,
E. H.
, and
Wakefield
,
W. C.
,
1997
, “
Measured Force/Current Relations in Solid Magnetic Thrust Bearings
,”
ASME J. Eng. Gas Turbines Power
,
119
, pp.
131
–
142
.
12.
Allaire, P. E., et al., 1988, “Design and Testing of a Magnetic Thrust Bearing,” Proceedings of the NASA Workshop on Magnetic Suspension Technology.
13.
Na
,
U. J.
, and
Palazzolo
,
A. B.
,
2000
, “
Optimized Realization of Fault-Tolerant Heteropolar Magnetic Bearings
,”
ASME J. Vibr. Acoust.
,
122
, pp.
209
–
221
.
14.
Na
,
U. J.
, and
Palazzolo
,
A. B.
,
2000
, “
Fault Tolerance of Magnetic Bearings With Material Path Reluctance and Fringing Factors
,”
IEEE Trans Magn.
,
36
, pp.
3939
–
3946
.
15.
Keith
,
F. J.
,
Williams
,
R. D.
, and
Allaire
,
P. E.
,
1990
, “
Digital Control of Magnetic Bearings Supporting a Multimass Flexible Rotor
,”
STLE Tribol. Trans.
,
33
, pp.
307
–
314
.
Copyright © 2001
 by ASME
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