Design, Modeling, Fabrication, Back-to-Back Test of a Magnetic Bearing System for High-Speed BLDCM Application

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Bangcheng Han ◽  
Shiqiang Zheng
Keyword(s):  
High Speed ◽  
Mechanical Design ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Resistive Load ◽  
Test Results ◽  
Test Setup ◽  
Brushless Dc ◽  
Amb System ◽  
Rotor Assembly

This paper describes in detail the design, construction, and testing of an active magnetic bearing (AMB) system for high-speed permanent magnet (PM) brushless DC motor (BLDCM) application. A back-to-back (BTB) test setup which consists of two BLDCMs connected by a high-speed flexible coupling is designed and built: the first one acts as the motor and the other one acts as the generator with resistive load. The dynamic model of the rigid rotor supported by AMBs, and its electromagnetic and feedback control design aspects are also provided. Mechanical design aspects are rotor assembly, radial AMB (RAMB), and thrust AMB (TAMB). Finally, full-loaded test results of the AMBs are given using the BTB experimental test setup that adopts two 100 kW electric machines supported by AMBs.

Test Results and Analytical Predictions for Rotor Drop Testing of an Active Magnetic Bearing Expander/Generator

2006 ◽  
Vol 129 (2) ◽  
pp. 522-529 ◽  
Author(s):  
Lawrence Hawkins ◽  
Alexei Filatov ◽  
Shamim Imani ◽  
Darren Prosser
Keyword(s):  
High Speed ◽  
High Performance ◽  
Time History ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Test Results ◽  
Direct Drive ◽  
Flow Loop ◽  
Low Loss ◽  
Full Speed

A cryogenic gas expander system that incorporates a high-performance, high-speed permanent magnet, direct-drive generator and low loss magnetic bearings is described. Flow loop testing to 30,000rpm was completed at the system manufacturer’s facility in January 2005, and field installation is scheduled for October 2005. As part of the system testing, the rotor was dropped onto the backup bearings multiple times at an intermediate speed and at 30,000rpm. Orbit and time-history data from a full speed drop and spin down are presented and discussed in detail. A transient, nonlinear rotordynamic analysis simulation model was developed for the machine to provide insight into the dynamic behavior. The model includes the dead band clearance, the flexible backup bearing support, and hard stop. Model predictions are discussed relative to the test data.

scholarly journals Adaptive Spindle Balancing Using Magnetically Levitated Bearings

1999 ◽  
Author(s):  
Patrick Barney ◽  
James Lauffer ◽  
James Redmond ◽  
William Sullivan ◽  
Rebecca Petteys
Keyword(s):  
High Speed ◽  
System Analysis ◽  
High Vacuum ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Physical Contact ◽  
Frictional Drag ◽  
Experimental Implementation ◽  
Amb System ◽  
Differential Control

Abstract A technological break through for supporting rotating shafts is the active magnetic bearing (AMB). Active magnetic bearings offer some important advantages over conventional ball, roller or journal bearings such as reduced frictional drag, no physical contact in the bearing, no need for lubricants, compatibility with high vacuum and ultra-clean environments, and ability to control shaft position within the bearing. The disadvantages of the AMB system are the increased cost and complexity, reduced bearing stiffness and the need for a controller. Still, there are certain applications, such as high speed machining, biomedical devices, and gyroscopes, where the additional cost of an AMB system can be justified. The inherent actuator capabilities of the AMB offer the potential for active balancing of spindles and micro-shaping capabilities for machine tools. The work presented in this paper concentrates on an AMB test program that utilizes the actuator capability to dynamically balance a spindle. In this study, an unbalanced AMB spindle system was enhanced with an LMS (Least Mean Squares) algorithm combined with an existing PID (proportional, integral, differential) control. This enhanced controller significantly improved the concentricity of an intentionally unbalanced shaft. The study included dynamic system analysis, test validation, control design and simulation, as well as experimental implementation using a digital LMS controller.

Influences of Assault Blocks on Rotor Vibrations in AMB System

2015 ◽  
Vol 9 (1) ◽  
pp. 496-503
Author(s):  
Zhu Yili ◽  
Zhang Yongchun
Keyword(s):  
High Speed ◽  
Dynamic Models ◽  
Dynamic Stiffness ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Control Methods ◽  
Rotor Vibration ◽  
Dynamic Simulations ◽  
Amb System ◽  
Theoretical Results

In an active magnetic bearing (AMB) system, the rotor always rotates at extremely high speed which always accompany with huge vibrations and noises. Most of the former researches associated with reducing the rotor vibrations are mainly focused on the control methods of AMB. A new method of installing series of assault blocks in the rotor is proposed to reduce the rotor vibrations. Firstly, the dynamic models of rotor supported by AMB considering the influences of assault blocks are established. Then, both dynamic simulations with and without assault blocks are carried out separately using the real-time AMB support dynamic stiffness. The rotor vibration displacements are mainly analyzed. Finally, relevant experiments are made to verify the theoretical results. Both theoretical and experimental results validated the advantages of using assault blocks.

Preliminary Research of Auxiliary Bearing in HTR-10GT Project

2008 ◽  
Author(s):  
Qingquan Qin ◽  
Guojun Yang ◽  
Zhengang Shi ◽  
Suyuan Yu
Keyword(s):  
Reference Value ◽  
Free Fall ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Main Function ◽  
Test Results ◽  
Test Rig ◽  
Advantages And Disadvantages ◽  
Auxiliary Bearing ◽  
Amb System

Active Magnetic Bearing (AMB) was used in the project of 10MW high temperature gas-cooled reactor (HTR-10GT) for the advantages over conventional mechanical bearings: without any mechanical friction and lubrication, etc. Auxiliary Bearings (ABs) is one of the most important parts in the AMB system, and its main function is to support the rotor at rest and provide protection for the rotor system during an overload or magnetic bearings failure situation. This paper introduced auxiliary bearings used in the HTR-10GT project and compared its advantages and disadvantages with other types of auxiliary bearings. The dynamic behaviors and temperature variation are the most important factors that may affect the performance of auxiliary bearings in a rotor drop event, this paper also analyzed the touching down course and dynamics in detail, divided the drop down process into four distinct stages of motion: free fall, impact, sliding-whirling and rolling. Finally, a test rig built up for the following rotor drop test is presented in the article. Test results at lower drop down speed were discussed. The result of the theory and experiment research has important reference value for the auxiliary bearings design of HTR-10GT.

Development of Exclusive Controller and HILS for Active Magnetic Bearing System

2012 ◽  
Vol 241-244 ◽  
pp. 1365-1369
Author(s):  
Seok Jo Go ◽  
Chi Yen Kim ◽  
Min Kyu Park ◽  
Young Jin Lee ◽  
Bin Yao
Keyword(s):  
High Speed ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
System Response ◽  
Current Output ◽  
Linear Current ◽  
Amb System ◽  
Fast Control ◽  
And Control ◽  
Bearing System

The active magnetic bearing system has been studied for long period. Comparing with long research history, the AMB application into industrial field is shown slowly for various causes. One of primary factor is to make up exclusive controller which can generate fast linear current output. Thus, this paper developed the exclusive AMB controller mounted high speed DSP which can operate so fast control calculation that improve system response ability. Especially, to consider the fusion of AMB system and control software, the development is conducted in HILS system with dSPACE from the beginning. Although HILS system is adopted, the developed ABM controller simplified the whole system and could make up optimized control algorithm promptly by measuring and applying the system gain and characteristics of them monitored by the HILS system in real time.

Low Power Consumption Nonlinear Control with H∞ Compensator for a Zero-Bias Flywheel AMB System

2004 ◽  
Vol 10 (8) ◽  
pp. 1151-1166 ◽  
Author(s):  
S. Sivrioglu ◽  
K. Nonami ◽  
M. Saigo
Keyword(s):  
Power Consumption ◽  
Nonlinear Control ◽  
Digital Signal Processor ◽  
High Speed ◽  
Digital Signal ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Zero Bias ◽  
Control Approach ◽  
Amb System

A nonlinear control approach based on a control current switching rule is studied experimentally for an energy storage flywheel active magnetic bearing (AMB) system. In the proposed control, only one electromagnet in each axis of the AMB has a current flow at any given time, depending on the rotor displacement. This results in a power consumption that is lower than a linear control employing a bias current. The equation of motion for the rigid rotor-AMB system is transformed to have a decentralized structure for the control design. To compute nonlinear control currents, an H ∞ compensator is designed for each axis of the AMB. The proposed approach is experimentally verified using a high-speed digital signal processor.

Some Nonlinear Effects of Magnetic Bearings

1999 ◽  
Author(s):  
Norbert Steinschaden ◽  
Helmut Springer
Keyword(s):  
Equations Of Motion ◽  
Period Doubling ◽  
Path Following ◽  
Nonlinear Effects ◽  
Magnetic Bearing ◽  
Operating Conditions ◽  
Active Magnetic Bearing ◽  
Nonlinear Phenomena ◽  
Amb System ◽  
Large Rotor

Abstract In order to get a better understanding of the dynamics of active magnetic bearing (AMB) systems under extreme operating conditions a simple, nonlinear model for a radial AMB system is investigated. Instead of the common way of linearizing the magnetic forces at the center position of the rotor with respect to rotor displacement and coil current, the fully nonlinear force to displacement and the force to current characteristics are used. The AMB system is excited by unbalance forces of the rotor. Especially for the case of large rotor eccentricities, causing large rotor displacements, the behaviour of the system is discussed. A path-following analysis of the equations of motion shows that for some combinations of parameters well-known nonlinear phenomena may occur, as, for example, symmetry breaking, period doubling and even regions of global instability can be observed.

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