scholarly journals The Impact Analysis of Beating Vibration for Active Magnetic Bearing

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 134104-134112 ◽  
Author(s):  
Hui Gao ◽  
Xianhai Meng ◽  
Kejun Qian
Keyword(s):  
Impact Analysis ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
The Impact

A Field Balancing Technique Based on Virtual Trial-Weights Method for a Magnetically Levitated Flexible Rotor

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
Yingguang Wang ◽  
Jiancheng Fang ◽  
Shiqiang Zheng
Keyword(s):  
High Efficiency ◽  
Notch Filter ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
New Method ◽  
Mode Shapes ◽  
Flexible Rotor ◽  
Magnetically Levitated ◽  
Balancing Efficiency ◽  
The Impact

For a magnetically levitated flexible rotor (MLFR), the amount of residual imbalance not only generates undesired vibrations, but also results in excessive bending, which may cause it hit to the auxiliary bearings. Thus, balancing below the critical speed is essential for the MLFR to prevent the impact. This paper proposes a balancing method of high precision and high efficiency, basing on virtual trial-weights. First, to reduce the computed error of rotor's mode shapes, a synchronous notch filter is inserted into the active magnetic bearing (AMB) controller, achieving a free support status. Then, AMBs provide the rotor with the synchronous electromagnetic forces (SEFs) to simulate the trial-weights. The SEFs with the initial angles varying from 0 deg to 360 deg in the rotational frame system result in continuous changes in the MLFR's deflection. Last, correction masses are calculated according to the changes. Compared to the trail-weights method, the new method needs not test-runs, which improves the balancing efficiency. Compared to the no trail-weights method, the new method does not require a precise model of the rotor-bearing system, which is difficult to acquire in the real system. Experiment results show that the novel method can reduce the residual imbalance effectively and accurately.

The Impact Analysis of Digital Controller Hardware Parameters of AMB on Control Precision

2012 ◽  
Vol 150 ◽  
pp. 111-115
Author(s):  
Yu Min Yang ◽  
Xi Ping Wang ◽  
Li Guo ◽  
Man Fan
Keyword(s):  
Digital Control ◽  
Impact Analysis ◽  
Control Model ◽  
Magnetic Bearing ◽  
Numerical Control ◽  
Digital Controller ◽  
Numerical Control System ◽  
Control Precision ◽  
The Impact ◽  
Control Accuracy

Digital control circuit for the hardware components, the impact of parameters on the control precision is analyzed. The digital control model is derived according to the requirements control of magnetic bearing system in this paper .Control accuracy and the prediction of control accuracy can be achieved by he theoretical estimates when numerical control system is given .For the future, it provides a simple and efficient method for estimating control accuracy of numerical controller.

Dynamic Analysis of Active Magnetic Bearing Rotor Dropping on Auto-eliminating Clearance Auxiliary Bearing Devices

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Chengtao Yu ◽  
Chaowu Jin ◽  
Xudong Yu ◽  
Longxiang Xu
Keyword(s):  
Dynamic Models ◽  
Ball Bearing ◽  
Experimental Studies ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Grease Lubrication ◽  
Successful Operation ◽  
Convex Shape ◽  
Auxiliary Bearing ◽  
The Impact

Auto-eliminating clearance auxiliary bearing devices (ACABD) can automatically eliminate the protective clearance between the ball bearing's outer race and the ACABD's supports, thus recenter the rotor when active magnetic bearing (AMB) system fails. This paper introduces the mechanical structure and working principles of the ACABD. When the rotor drops, numerical and experimental studies on the transient responses of the rotor and the ACABD's supports are also conducted as follows. First, we propose an equivalent clearance circle method to establish dynamic models of rotor dropping on the ACABD. Based on these models, the rotor dropping simulations are carried out to investigate the modes of lubrication and the ACABD's support shape's influences on the performance and execution time of clearance elimination. Second, various AMB rotor dropping tests are performed on our experimental setup with different ACABD supporting conditions. Indicated from the basically consistent simulation and experimental results, the correctness of the theoretical analysis and the successful operation of ACABD have been verified. Moreover, with the grease lubrication in the ball bearing and convex shape supports, the ACABD can eliminate the protective clearance within approximately 0.5 s upon the rotor drops and then sustain the rotor to operate stably around its original rotation center. Because of clearance elimination, the dramatic impact between the ball bearing and the supports is avoided and the impact forces among each part are effectively reduced. Meanwhile, the possibility of incurring full-clearance backward whirling motion is eliminated.

scholarly journals Nonlinear Dynamics and Motion Bifurcations of the Rotor Active Magnetic Bearings System with a New Control Scheme and Rub-Impact Force

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1502
Author(s):  
Nasser Abul-Fadeel Saeed ◽  
Emad Mahrous ◽  
Emad Abouel Nasr ◽  
Jan Awrejcewicz
Keyword(s):  
Control Method ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Rotating Disc ◽  
Nonlinear Dynamical ◽  
Dynamic Friction Coefficient ◽  
Impact Forces ◽  
Control Scheme ◽  
The Impact ◽  
First Time

This article is dedicated to investigating the nonlinear dynamical behaviors of the 8-pole rotor active magnetic bearing system. The rub and impact forces between the rotating disc and the pole-legs are included in the studied model for the first time. A new control scheme based on modifying the 8-pole positions has been introduced. The proposed control methodology is designed such that four poles only are located in the horizontal and vertical directions (i.e., in +X,+Y,−X,−Y directions), while the other four poles are inserted in a way such that each pole makes 45° with two of the axes +X,+Y,−X,−Y. The control currents in the horizontal and vertical poles are suggested to be proportional to both the velocity and displacement of the rotor in the horizontal and vertical directions, respectively, while the control currents in the inclined poles are proposed to be dependent on the combination of both the displacement and velocity of the rotor in the horizontal and vertical directions. Accordingly, the whole-system mathematical model is derived. The derived discontinuous dynamical system is analyzed employing perturbation methods, Poincare maps, bifurcation diagrams, whirling orbits, and frequency spectrum. The obtained results demonstrated that the controller proportional control gain can play a significant role in changing the vibratory behaviors of the system, where the proposed control method can behave either as a cartesian control strategy or as a radial control one depending on the magnitude of the proportional gain. In addition, it is found that the rotor system can vibrate with periodic, periodic-n, quasiperiodic, or chaotic motion when the rub and/or impact forces occur. Moreover, it is reported for the first time that the rotor-AMB can oscillate symmetrically in X and Y directions either in full annular rub mode or quasiperiodic partial rub mode depending on the impact stiffness coefficient and the dynamic friction coefficient.

Research on Auxiliary Bearing Structure With Buffer Shim Based on LS-DYNA for Helium Circulator of HTR-10

2018 ◽  
Author(s):  
Guojun Yang ◽  
Zhe Sun ◽  
Xingnan Liu ◽  
Zhengang Shi
Keyword(s):  
Stress Distribution ◽  
Impact Load ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Structure Characteristic ◽  
System A ◽  
Huge Impact ◽  
Auxiliary Bearing ◽  
The Impact ◽  
Bearing Structure

The active magnetic bearing (AMB) is introduced to the helium circulator of the 10 MW high temperature gas-cooled reactor (HTR-10). Auxiliary bearing bears huge instantaneous impact load when the AMB fails to work in the helium circulator. The huge load may cause serious damage to the auxiliary bearing. In order to reduce the impact load and protect the AMB and rotor system, a new type of auxiliary bearing with axial buffer shim is presented in this paper. There are two different structures of auxiliary bearing to be studied in the paper. One is the auxiliary bearing with the buffer shim and another one is without the buffer shim. The finite element method and LS-DYNA software are applied to analyze the structure characteristic of the auxiliary bearing. The rotor dropping trajectory and the stress distribution of the auxiliary bearing are analyzed by comparing two different auxiliary bearing structures during the rotor drop. The stress change of the auxiliary bearing in each impact course is mainly studied, and the law of stress variation in impact course is analyzed. Besides, the stress distribution and deformation of two auxiliary bearing is the focus research when impact force is maximum in the paper. Finally, the research shows the auxiliary bearing structure without the buffer shim can bear the huge impact of the rotor drop, and the addition of buffer shim can also reduce the damage of the rotor drop to the auxiliary bearing structure. These researches’ result provides an important reference for the experiment of rotor drop, and has laid a theoretical foundation for the practical application of this structure.

The Impact of a Potential Public/Private Initiative on a Defined Region of the South Suburban Chicago Metropolitan Area

2019 ◽  
pp. 14-32
Keyword(s):  
Supply Chain ◽  
Economic Impact ◽  
Impact Analysis ◽  
Census Data ◽  
Economic Benefits ◽  
Local Economy ◽  
Market Area ◽  
State And Local ◽  
The University ◽  
The Impact

The university is considered one of the engines of growth in a local economy or its market area, since its direct contributions consist of 1) employment of faculty and staff, 2) services to students, and supply chain links vendors, all of which define the University’s Market area. Indirect contributions consist of those agents associated with the university in terms of community and civic events. Each of these activities represent economic benefits to their host communities and can be classified as the economic impact a university has on its local economy and whose spatial market area includes each of the above agents. In addition are the critical links to the University, which can be considered part of its Demand and Supply chain. This paper contributes to the field of Public/Private Impact Analysis, which is used to substantiate the social and economic benefits of cooperating for economic resources. We use Census data on Output of Goods and Services, Labor Income on Salaries, Wages and Benefits, Indirect State and Local Taxes, Property Tax Revenue, Population, and Inter-Industry to measure economic impact (Implan, 2016).

Impact Analysis of the Mechanization Program for Tribal Paddy Farmers of Goa

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
MATHALA JULIET GUPTA ◽  
ASHISH M. PITRE ◽  
SUMATI CHAVAN PANDURNAG ◽  
SALONI SALIL VANJARI
Keyword(s):  
Impact Analysis ◽  
Field Capacity ◽  
Significant Saving ◽  
Manual Methods ◽  
Paddy Farmers ◽  
The Impact ◽  
And Training

This paper assessed the impact of the mechanization of the 8 tribal paddy farmers’ groups of Goa benefited in the year 2011 through the Tribal sub-plan program of ICAR-CCARI through results of surveys conducted in 2012 and 2015. Shift to mechanization among beneficiaries was significant in power tillers (64-100%) but less in power reapers(0-91%). Also significant saving in manpower (Power tillers:33.3% to 60%, power reapers: 33.3% to 83.3%), , time (field capacity increased (power tillers : 41.7% to141%, power reapers :58.1% to 912.8%) and cost(power tillers :44.7% to 59.1%, power reapers : 57.8% to 82.9%) was reportedthrough the use of equipment as compared to desi plough or manual methods of harvesting. Some constraints like lack of access roads and training in use and maintenance of the equipment were reported by the beneficiary farmers.

scholarly journals Application of the Dynamic Iterative Learning Control to the Heteroplanar Active Magnetic Bearing

2020 ◽  
Vol 53 (2) ◽  
pp. 1511-1516
Author(s):  
Lukasz Hladowski ◽  
Arkadiusz Mystkowski ◽  
Krzysztof Galkowski ◽  
Eric Rogers ◽  
Bing Chu
Keyword(s):  
Iterative Learning Control ◽  
Learning Control ◽  
Magnetic Bearing ◽  
Iterative Learning ◽  
Active Magnetic Bearing
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