Experiences using RT-Linux to implement a controller for a high speed magnetic bearing system

2003 ◽  
Author(s):  
M. Humphrey ◽  
E. Hilton ◽  
P. Allaire
Keyword(s):  
High Speed ◽  
Magnetic Bearing ◽  
Bearing System

Performance of a Foil-Magnetic Hybrid Bearing

2000 ◽  
Author(s):  
Erik E. Swanson ◽  
Hooshang Heshmat ◽  
James Walton
Keyword(s):  
High Speed ◽  
Load Capacity ◽  
Magnetic Bearing ◽  
Experimental Program ◽  
Turbine Engine ◽  
Foil Bearing ◽  
Speed Performance ◽  
Hybrid Bearing ◽  
High Load Capacity ◽  
Bearing System

To meet the advanced bearing needs of modern turbomachinery, a hybrid foil-magnetic hybrid bearing system was designed, fabricated and tested in a test rig designed to simulate the rotor dynamics of a small gas turbine engine (31 kN to 53 kN thrust class). This oil-free bearing system combines the excellent low and zero-speed capabilities of the magnetic bearing with the high load capacity and high speed performance of the compliant foil bearing. An experimental program is described which documents the capabilities of the bearing system for sharing load during operation at up to 30,000 RPM and the foil bearing component’s ability to function as a back-up in case of magnetic bearing failure. At an operating speed of 22,000 RPM, loads exceeding 5300 N were carried by the system. This load sharing could be manipulated by an especially designed electronic control algorithm. In all tests, rotor excursions were small and stable. During deliberately staged magnetic bearing malfunctions, the foil bearing proved capable of supporting the rotor during continued operation at full load and speed, as well as allowing a safe rotor coast-down. The hybrid system tripled the load capacity of the magnetic bearing alone and can offer a significant reduction in total bearing weight compared to a comparable magnetic bearing.

scholarly journals Design and Implementation of a Fault-Tolerant Magnetic Bearing System for MSCMG

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Enqiong Tang ◽  
Bangcheng Han
Keyword(s):  
High Speed ◽  
Fault Tolerant ◽  
Control Strategies ◽  
Load Capacity ◽  
Maximum Load ◽  
Magnetic Bearing ◽  
Before And After ◽  
Key Factor ◽  
Gyroscopic Coupling ◽  
Bearing System

The magnetically suspended control moment gyros (MSCMGs) are complex system with multivariable, nonlinear, and strongly gyroscopic coupling. Therefore, its reliability is a key factor to determine whether it can be widely used in spacecraft. Fault-tolerant magnetic bearing systems have been proposed so that the system can operate normally in spite of some faults in the system. However, the conventional magnetic bearing and fault-tolerant control strategies are not suitable for the MSCMGs because of the moving-gimbal effects and requirement of the maximum load capacity after failure. A novel fault-tolerant magnetic bearing system which has low power loss and good robust performances to reject the moving-gimbal effects is presented in this paper. Moreover, its maximum load capacity is unchanged before and after failure. In addition, the compensation filters are designed to improve the bandwidth of the amplifiers so that the nutation stability of the high-speed rotor cannot be affected by the increasing of the coil currents. The experimental results show the effectiveness and superiority of the proposed fault-tolerant system.

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.

Effects of the Magnetic Damper Locations on Dynamic Characteristics of the Active Magnetic Bearing System in Manufacturing Engineering

2012 ◽  
Vol 252 ◽  
pp. 51-55
Author(s):  
Zhen Yu Xie ◽  
Hong Kai Zhou ◽  
Xiao Wang
Keyword(s):  
Dynamic Characteristics ◽  
High Speed ◽  
Magnetic Bearing ◽  
Magnetic Bearings ◽  
Active Magnetic Bearing ◽  
Active Magnetic Bearings ◽  
Actual Operation ◽  
And Control ◽  
System Operating ◽  
Bearing System

The magnetic damper was introduced into the high speed rotating machinery to restrain the vibration of the rotor supported by active magnetic bearings. The experimental setup, which was made up of one rotor, two radial active magnetic bearings, one axial active magnetic bearing, one magnetic damper and control system, was built to investigate the effects of the magnetic damper locations on dynamic characteristics of the system by theoretical analysis, experimental modal analysis and actual operation of the system. The results show that the vibration of the active magnetic bearing system operating at the modal frequency can be reduced more effectively if the magnetic damper is located far from the nodes of the corresponding mode shape.

Floating Shock Platform Testing of a Magnetic Bearing Supported Chiller Compressor: Measurements and Simulation Results

2018 ◽  
Author(s):  
Lawrence Hawkins ◽  
Zhiyang Wang ◽  
Koman Nambiar
Keyword(s):  
High Speed ◽  
Dynamic Models ◽  
Magnetic Bearing ◽  
Magnetic Bearings ◽  
Direct Drive ◽  
Structural Dynamic ◽  
Shock Testing ◽  
Shock Impacts ◽  
Standby Mode ◽  
Bearing System

Qualification shock testing has been completed for a new chilled water plant developed for the US Navy. The variable speed compressor at the heart of the chiller system includes a direct drive, high-speed permanent magnet (PM) motor, PM bias active magnetic bearings, and a backup bearing system. For MIL-S-901D shock certification, the chiller was mounted on a Navy floating shock platform (barge) and subjected to a standard sequence of four different shock impacts generated from high explosive charges from varying angles and standoff distances. The chiller was fully operational during three blasts and in standby mode for the fourth blast. In the standby mode, the shaft is de levitated and stationary on the backup bearings and the chiller secured. The backup bearing system of the motor absorbed the response to the shock impacts and the magnetic bearings subsequently recovered levitation as designed. The shock testing was simulated using a transient, nonlinear rotordynamic analysis including the magnetic bearing control and saturation features, backup bearings with resilient mounts and associated clearances, and structural dynamic models of the rotor and housing. Compressor/motor housing acceleration measured during the testing was used as the driving input into the simulation. Some rotor position data recorded during shock testing, the simulation approach and comparisons are reported and discussed.

Rotor Design for High Speed PM Machine Based on Riccati Transfer Matrix Method

2011 ◽  
Vol 383-390 ◽  
pp. 337-343
Author(s):  
Ji Qiang Wang ◽  
Feng Xiang Wang
Keyword(s):  
Magnetic Properties ◽  
High Speed ◽  
Magnetic Bearing ◽  
Vibration Modes ◽  
Test Results ◽  
Rotor Design ◽  
Transfer Method ◽  
Rotor Structure ◽  
Bearing System

The rotor under study is a PM rotor of a synchronous machine intended for operation at 60 000 rpm. It is well known that design of high speed permanent magnetic (PM) rotor is quite different from that of a normal PM rotor. The determination of the rotor structure and dimensions must take consideration of the strength, stiffness and the magnetic properties of the PM rotor. Based on the Riccati transfer method, the dynamic model of the rotor-bearing system has been established. Then the supporting stiffness of the magnetic bearing is estimated and the PM rotor’s critical speeds and the corresponding vibration modes have been found. A prototype has been built and some test results proved the correct of the calculation.

A Magnetic Bearing System for More-Electric Engines

2000 ◽  
Author(s):  
R. Jett Field ◽  
Christopher K. Sortore ◽  
Victor Iannello
Keyword(s):  
High Speed ◽  
High Performance ◽  
Fault Tolerant ◽  
High Reliability ◽  
Industrial Applications ◽  
Magnetic Bearing ◽  
Tip Clearance ◽  
Critical Components ◽  
Maintenance Requirements ◽  
Bearing System

Magnetic bearing systems for more-electric engines (MEEs) are under development for aircraft and industrial applications to improve performance and reduce maintenance requirements. Key features of the magnetic bearing system are high performance, high temperature actuators with integrated sensors; a high speed digital controller; a high reliability, fault-tolerant system architecture; modular amplifiers; active control of tip clearance; and adaptive control algorithms. Critical components of the magnetic bearing system have been demonstrated in an engine manufacturer’s rotordynamic test stand and other components are in various stages of development.

Touchdown Bearing Development for a Magnetic Bearing System Used in a High Temperature Gas Turbine

1997 ◽  
Author(s):  
Francis P. Marchand
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
High Speed ◽  
Magnetic Bearing ◽  
Total System ◽  
Bearing Materials ◽  
Design Options ◽  
The Impact ◽  
Bearing System ◽  
High Temperature Gas

This papers describes the design and development of a touchdown bearing system. The touchdown bearing is one of the important elements in any high speed magnetic bearing system. The touchdown bearing functions to fully off-load or load share with the magnetic bearing and prevent catastrophic system failures. The proper design of this component is a critical step in the design of the total system and was not treated as a stand-alone sub-component. The impact loads which these bearings have to endure is a challenge to the designer. The high temperature environment on this bearing adds additional constraints to the design options which the designer has to work with. A design was produced, which will function under these conditions. The use of silicon nitride balls with sliver coated CPM Rex 20 races will be described. The bearing is mounted on a replaceable journal, which in turn is mounted on the magnetic bearing. Design and test data for use of these bearing materials in a high temperature gas turbine application is included in this paper.

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