Fault tolerance of magnetic bearings by generalized bias current linearization

1995 ◽  
Vol 31 (3) ◽  
pp. 2304-2314 ◽  
Author(s):  
E.H. Maslen ◽  
D.C. Meeker
Keyword(s):  
Fault Tolerance ◽  
Bias Current ◽  
Magnetic Bearings

scholarly journals A Parametric Solution to the Generalized Bias Linearization Problem

Actuators ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 14 ◽  
Author(s):  
David Meeker ◽  
Eric Maslen
Keyword(s):  
Analytical Solution ◽  
Bias Current ◽  
Magnetic Bearings ◽  
Parametric Solution ◽  
Equal Area ◽  
Analytical Computation ◽  
Linearization Problem

Previously, a generalized bias current linearization was presented for the control of radial magnetic bearings. However, a numerically intensive procedure was required to obtain bias linearization currents. The present work develops an analytical solution to the generalized bias linearization problem in which solutions are indexed by a small number of parameters. The formulation also permits the analytical computation of bias linearization currents for faulted-coil cases. A limitation of the solution presented is that it only applies to stators with an even number of evenly spaces poles of equal area.

Fault Tolerant Magnetic Bearings

1999 ◽  
Vol 121 (3) ◽  
pp. 504-508 ◽  
Author(s):  
E. H. Maslen ◽  
C. K. Sortore ◽  
G. T. Gillies ◽  
R. D. Williams ◽  
S. J. Fedigan ◽  
...  
Keyword(s):  
Fault Tolerance ◽  
High Speed ◽  
Fault Tolerant ◽  
High Capacity ◽  
Magnetic Bearing ◽  
Magnetic Bearings ◽  
Flexible Rotor ◽  
Variable Reluctance ◽  
Modular Redundancy ◽  
Bearing System

A fault tolerant magnetic bearing system was developed and demonstrated on a large flexible-rotor test rig. The bearing system comprises a high speed, fault tolerant digital controller, three high capacity radial magnetic bearings, one thrust bearing, conventional variable reluctance position sensors, and an array of commercial switching amplifiers. Controller fault tolerance is achieved through a very high speed voting mechanism which implements triple modular redundancy with a powered spare CPU, thereby permitting failure of up to three CPU modules without system failure. Amplifier/cabling/coil fault tolerance is achieved by using a separate power amplifier for each bearing coil and permitting amplifier reconfiguration by the controller upon detection of faults. This allows hot replacement of failed amplifiers without any system degradation and without providing any excess amplifier kVA capacity over the nominal system requirement. Implemented on a large (2440 mm in length) flexible rotor, the system shows excellent rejection of faults including the failure of three CPUs as well as failure of two adjacent amplifiers (or cabling) controlling an entire stator quadrant.

scholarly journals Evaluation of the Topology of Switching Power Amplifiers for Active Magnetic Bearings

Proceedings ◽  
2020 ◽  
Vol 64 (1) ◽  
pp. 25
Author(s):  
Yefa Hu ◽  
Kezhen Yang ◽  
Xinhua Guo ◽  
Jian Zhou ◽  
Huachun Wu
Keyword(s):  
Power Amplifier ◽  
Power Amplifiers ◽  
Comprehensive Evaluation ◽  
Magnetic Bearing ◽  
Bias Current ◽  
Magnetic Bearings ◽  
Active Magnetic Bearing ◽  
Active Magnetic Bearings ◽  
Switching Power ◽  
Bearing System

A switching power amplifier is a key component of the actuator of an active magnetic bearing, and its reliability has an important impact on the performance of a magnetic bearing system. This paper analyzes the topologies of a switching power amplifier of an active magnetic bearing. In the case of different coil pair arrangements and bias current distributions, comprehensive evaluation of the different topologies of switching power amplifiers is introduced. This evaluation has a guiding role in the design of a switching power amplifier of an active magnetic bearing.

scholarly journals Self-Sensing Active Magnetic Bearings with Zero-Bias-Current Control

2006 ◽  
Vol 126 (10) ◽  
pp. 1399-1405 ◽  
Author(s):  
Yuki Kato ◽  
Toshiya Yoshida ◽  
Katsumi Ohniwa
Keyword(s):  
Bias Current ◽  
Current Control ◽  
Magnetic Bearings ◽  
Active Magnetic Bearings ◽  
Zero Bias

Self‐sensing active magnetic bearings with zero‐bias‐current control

2008 ◽  
Vol 165 (2) ◽  
pp. 69-76 ◽  
Author(s):  
Yuki Kato ◽  
Toshiya Yoshida ◽  
Katsumi Ohniwa
Keyword(s):  
Bias Current ◽  
Current Control ◽  
Magnetic Bearings ◽  
Active Magnetic Bearings ◽  
Zero Bias

Variable Bias Current in Magnetic Bearings for Energy Optimization

2007 ◽  
Vol 43 (3) ◽  
pp. 1052-1060 ◽  
Author(s):  
M. Necip Sahinkaya ◽  
Ahu E. Hartavi
Keyword(s):  
Energy Optimization ◽  
Bias Current ◽  
Magnetic Bearings ◽  
Variable Bias
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