Development of a Compact, Light Weight Magnetic Bearing

1990 ◽  
Author(s):  
Crawford Meeks ◽  
Victor Spencer
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Permanent Magnets ◽  
Magnetic Bearing ◽  
Test Model ◽  
Light Weight ◽  
New Approach ◽  
Bearing Design ◽  
And Control ◽  
Permanent Magnet Field

A novel magnetic bearing design was created that uses permanent magnets to generate the primary magnetic field and attraction electromagnets for stabilization and control. This approach uses a geometrically efficient arrangement with a combination of axially flowing permanent magnet field and a circumferentially flowing electromagnetic field. This design was compared analytically with other types of magnetic bearing designs. The design comparison showed the new design to be 50% lighter weight and 50% lower in power consumption than all electromagnetic designs of equivalent performance. A demonstration model of this new approach was built and tested for performance at low shaft speeds. This test model successfully demonstrated the feasibility of this new approach.

Parameter Design and Static Performance Analysis of a Novel Axial Magnetic Bearing for Maglev Wind Generators

2014 ◽  
Vol 703 ◽  
pp. 421-424 ◽  
Author(s):  
Jin Yue Dong ◽  
Yu Xin Sun ◽  
Huang Qiu Zhu
Keyword(s):  
Small Volume ◽  
Magnetic Circuit ◽  
Levitation Force ◽  
Magnetic Bearing ◽  
Parameter Design ◽  
Light Weight ◽  
Low Loss ◽  
Wind Generators ◽  
Static Performance ◽  
And Control

As an important component of maglev wind generators, magnetic bearing should possess the merits of small volume, light weight, lower consumption and so on. A novel low-loss axial hybrid magnetic bearing (HMB) is proposed in this paper, its structure and operation principle are introduced, and the process of producing suspension force is elaborated. Based on equivalent magnetic circuit method, magnetic circuit models of PM and control coil are analyzed and established to deduce the quotation of axial levitation force. The accuracy and the reasonableness of proposed low-loss axial HMB are analyzed and validated by using finite element method (FEM), and the comparison between theoretical calculation and FEM is given, which indicates the proposed HMB exhibits good dynamic response and easy control.

scholarly journals Experimental Research of Electromagnetic Field Influence on Digital Temperature Sensors with Single-Wire Lines to Study Possibility of Their Use in NPP Control Systems

2019 ◽  
pp. 14-18
Author(s):  
Yu. Bykovsky ◽  
V. Levchenko ◽  
O. Pogosov
Keyword(s):  
Electromagnetic Field ◽  
Temperature Sensors ◽  
Operating Conditions ◽  
Temperature Fields ◽  
Auxiliary Equipment ◽  
New Approach ◽  
Metrological Control ◽  
Control Technologies ◽  
Technical Interest ◽  
And Control

Issues related to the introduction of new control technologies and temperature monitoring at NPPs are being considered, since NPP longterm operation depends on the reliability of process control means. It is promising to build instrumentation and control complexes using one-wire technologies, since the operation information removal and transmission means should be carried out under the conditions of spatial constraints on the location of cabling. One-wire technologies make it easy to build a measurement network of the most complex topology. It is proposed to use DS18B20 universal digital primary measuring transducers as NPP testing equipment. In this regard, scientific and technical interest is a new approach to the measurement of temperature fields based on 1-Wire technology. It was proposed to use UR-1 demagnetizer as a source of a variable electromagnetic field imitating NPP equipment operating conditions. The paper also presents a study for visualization of the generated electromagnetic fields. A Hall sensor is used for measuring the fields under consideration. The proposed method can be used to conduct other similar studies to assess the response of temperature sensors (or other digital sensors) to an external magnetic field. A visualization method is used to evaluate the informational function and a conclusion is made about the applicability of such sensors in the systems of metrological control and monitoring of NPP auxiliary equipment.

Design Analysis of a Spherical Magnetic Bearing for Multi-DOF Rotational Stage Applications

2007 ◽  
Author(s):  
Kok-Meng Lee ◽  
Hungsun Son ◽  
Jong-Kweon Park
Keyword(s):  
Magnetic Field ◽  
Magnetic Force ◽  
Magnetic Bearing ◽  
Control Performance ◽  
Closed Form Solutions ◽  
Precise Calculation ◽  
Dynamics And Control ◽  
And Control ◽  
The Magnetic Field ◽  
General Method

This paper presents an analytical method to facilitate design of a spherical magnetic bearing (SMB) for a multi-DOF rotational stage. Both passive and active regulations of the SMB are considered. We formulate the SMB dynamic model along with the method of computing the magnetic force and torque required to null any deviation of the rotor, which requires solving the magnetic field. For this, we introduce and validate a general method, referred to here as distributed-multi-pole (DMP) modeling method which requires only a limited set of known (numerical or experimental) field solutions, to derive closed-form solutions for precise calculation of the magnetic field around a permanent magnet (PM). The DMP method has been validated by comparing its modeled potential field and flux density against analytical solutions, as well as the computed force (using DMP modeled field) against published experimental data; both show excellent agreement. Finally, we demonstrate the concept feasibility of the spherical magnetic bearing, and analyze its dynamics and control performance using the DMP modeled field and computed force/torque.

Analysis and Control of a Flywheel Energy Storage System With a Hybrid Magnetic Bearing

1997 ◽  
Vol 119 (4) ◽  
pp. 650-656 ◽  
Author(s):  
J. D. Stienmier ◽  
S. C. Thielman ◽  
B. C. Fabien
Keyword(s):  
Energy Storage ◽  
Active Control ◽  
Permanent Magnets ◽  
Storage System ◽  
Equations Of Motion ◽  
Energy Storage System ◽  
Magnetic Bearing ◽  
Flywheel Energy Storage ◽  
Flywheel Energy Storage System ◽  
And Control

This article presents the design, dynamic analysis, and control of a flywheel energy storage system. At the heart of the system is a hybrid magnetic bearing. The bearing consists of ring and disk shaped permanent magnets, and a synthetic ruby sphere on a sapphire plate. The bearing is shown to be stable without active control. Equations of motion for the flywheel are derived in a sensor based coordinate system. The resulting equations are non-singular around the nominal operating condition and are feedback linearizable without the need for a coordinate transformation. A method of modeling rotor imbalance as a set of sinusoidal disturbances of magnitudes that do not depend on rotational speed is also presented. To reject large external disturbances active control is applied to the flywheel. Two nonlinear control laws are applied and are shown to improve the initial condition response of the inherently stable system.

Design and Control of Active Magnetic Bearing System With Lorentz Force Type Axial Actuator

2003 ◽  
Author(s):  
Ha-Yong Kim ◽  
Chong-Won Lee
Keyword(s):  
High Performance ◽  
Permanent Magnets ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Distribution Analysis ◽  
New Type ◽  
Radial Forces ◽  
Space Limitation ◽  
Amb System ◽  
And Control

As the size of 5-axis active magnetic bearing (AMB) gets smaller, the space limitation for installation of axial magnetic bearing unit becomes stringent. In this paper, a new type of compact, high-performance 5-axis AMB with solid cores and rotor is proposed, which consists of four permanent magnets, four U-shaped cores and 16 control coils. The proposed homopolar AMB system is levitated by the Lorentz type axial as well as Maxwell type radial forces. Based on the magnetic flux distribution analysis, the control algorithm is designed to account for the coupled effect between the radial and axial control fluxes. Experiments are also carried out with a prototype AMB system to validate the new design concept.

High Efficiency Radial Passive Magnetic Bearing

2010 ◽  
Vol 164 ◽  
pp. 360-365 ◽  
Author(s):  
Krzysztof Falkowski ◽  
Maciej Henzel
Keyword(s):  
Magnetic Field ◽  
Permanent Magnets ◽  
High Efficiency ◽  
Magnetic Levitation ◽  
Magnetic Bearing ◽  
Air Gap ◽  
The Other ◽  
Experimental Setup ◽  
Halbach Array ◽  
The Magnetic Field

Passive magnetic bearing with Halbach array is presented in this paper. The array uses permanent magnets with radial and axial magnetization to augment the magnetic field on one side of the array and cancel it on the other side. The design of the bearing consists of ring-shaped magnets of 60x70 mm and 75x85 mm with different orientation of magnetization. The designed passive magnetic bearing has air gap of 2.5 mm, stiffness 129297 N/m and maximal value of load 200 N. The bearing ensures magnetic levitation and stabilization of rotor in a work point. The paper presents the design of the passive magnetic bearing as well as the experimental setup together with investigation results.

Modeling and control of an unbalanced magnetic rotor-bearing system as a bearingless motor

2017 ◽  
Vol 34 (7) ◽  
pp. 2212-2227 ◽  
Author(s):  
Shyh-Leh Chen ◽  
Pei-Hua Lee ◽  
Chow-Shing Toh
Keyword(s):  
Permanent Magnets ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Content Type ◽  
Modeling And Control ◽  
Unbalanced Mass ◽  
Bearingless Motor ◽  
The Cost ◽  
And Control ◽  
Mass Type

Purpose This paper is concerned with the design and analysis of a bearingless motor. Design/methodology/approach The bearingless motor is obtained by a regular three-pole active magnetic bearing with an intentionally attached unbalanced mass on the rotor. It is the unbalanced mass that will generate the rotational torque for the motor function. Modeling and control of the unbalanced mass-type bearingless motor have been considered. Findings It is found through simulations that both functions of motor and magnetic bearing can indeed be achieved in this system. Originality/value This novel bearingless motor requires no additional windings and permanent magnets. Thus, it can greatly reduce the cost and design of the bearingless motor.

On-Surface Radical Oligomerisation: A New Approach to STM Tip-Induced Reactions

2018 ◽  
Author(s):  
Gaolei Zhan ◽  
Younes Makoudi ◽  
Judicael Jeannoutot ◽  
Simon Lamare ◽  
Michel Féron ◽  
...  
Keyword(s):  
Sample Surface ◽  
Scanning Tunnelling Microscope ◽  
Transfer Event ◽  
New Approach ◽  
The Past ◽  
Organic Nanostructures ◽  
Scanning Tunnelling ◽  
New Strategy ◽  
Surface Fabrication ◽  
And Control

Over the past decade, on-surface fabrication of organic nanostructures has been widely investigated for the development of molecular electronic devices, nanomachines, and new materials. Here, we introduce a new strategy to obtain alkyl oligomers in a controlled manner using on-surface radical oligomerisations that are triggered by the electrons/holes between the sample surface and the tip of a scanning tunnelling microscope. The resulting radical-mediated mechanism is substantiated by a detailed theoretical study. This electron transfer event only occurs when <i>V</i><sub>s</sub> < -3 V or <i>V</i><sub>s</sub> > + 3 V and allows access to reactive radical species under exceptionally mild conditions. This transfer can effectively ‘switch on’ a sequence leading to formation of oligomers of defined size distribution due to the on-surface confinement of reactive species. Our approach enables new ways to initiate and control radical oligomerisations with tunnelling electrons, leading to molecularly precise nanofabrication.

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