Unified approach to solving a steady-state electromagnetic field

1997 ◽  
Vol 33 (2) ◽  
pp. 1974-1977 ◽  
Author(s):  
M. Triep ◽  
B. Hribernik ◽  
L. Skrget
Keyword(s):  
Electromagnetic Field ◽  
Steady State ◽  
Unified Approach

Analysis of Vibration Caused by Electromagnetic Force on Stator End-Winding of Large Dry Submersible Motor

2013 ◽  
Vol 416-417 ◽  
pp. 428-432
Author(s):  
Li Shan ◽  
Xiao Wei Cheng ◽  
Yong Fang ◽  
Xiao Hua Bao
Keyword(s):  
Electromagnetic Field ◽  
Steady State ◽  
Transition State ◽  
Electromagnetic Force ◽  
Radial Displacement ◽  
Radial Direction ◽  
Axial Direction ◽  
Axial Displacement ◽  
Force Density ◽  
Submersible Motor

This paper investigates the vibration which caused by electromagnetic on the stator end-winding of the large dry submersible motor. Firstly, the electromagnetic field which included transition state and steady state is researched by 3-D FEM. Secondly, the electromagnetic force which lead to vibrations of end-winding is calculated by numerical method, it can be obtained that where endured the largest force density along the slant part of end-winding. Finally, the radial displacement and the axial displacement of the slant part which caused by vibrations is studied, the analysis results show that the axial displacement is larger than the amplitude of radial displacement. It indicates that the slant part of end-winding will be more easily damaged at axial direction than radial direction.

Force de répulsion entre un courant sinusoïdal linéique et une bande conductrice mince : application aux problèmes de lévitation

1994 ◽  
Vol 72 (9-10) ◽  
pp. 633-638
Author(s):  
M. T. Attaf ◽  
D. Allab
Keyword(s):  
Electromagnetic Field ◽  
Steady State ◽  
Electromagnetic Interaction ◽  
Practical Interest ◽  
Stationary Case ◽  
Electromagnetic Field Distribution ◽  
Conducting Plate ◽  
Conducting Materials ◽  
Sinusoidal Current ◽  
Repulsive Forces

In a previous work, the authors presented a semianalytical treatment of the electromagnetic field distribution in the case of a straight conductor carrying a sinusoidal current parallel to a thin conducting plate. The result of this investigation is extended here to the evaluation of the repulsive forces accompanying this type of electromagnetic interaction. The variation of such forces with geometric parameters is studied in the presence of a single conductor, and in the case of several conductors laying in a plane parallel to the surface of the material submitted to the induction phenomenon. The problem of lévitation in steady-state conditions is examined, in the light of this arrangement, for various conducting materials. Graphs illustrate the results obtained and make evident their practical interest particularly in the stationary case of magnetically levitated vehicles.

Steady-state correlations of two atoms interacting with a reservoir

2012 ◽  
Vol 12 (3&4) ◽  
pp. 231-252
Author(s):  
Luis Octavio Castanos
Keyword(s):  
Electromagnetic Field ◽  
Steady State ◽  
Master Equation ◽  
Field Intensity ◽  
Mixed State ◽  
Laser Field ◽  
Quantum Discord ◽  
Energy Levels ◽  
High Laser ◽  
X State

We consider two two-level atoms fixed at different positions, driven by a resonant monochromatic laser field, and interacting collectively with the quantum electromagnetic field. A Born-Markov-secular master equation is used to describe the dynamics of the two atoms and the steady-state is obtained analytically for a configuration of the atoms. The steady-state populations of the energy levels of the free atoms, entanglement, quantum and geometric discords and degree of mixedness are calculated analytically as a function of the laser field intensity and the distance between the two atoms. It is found that there is a possibility of considerable steady-state entanglement and left/right quantum discord and that these can be controlled either by increasing/decreasing the intensity of the laser field or by increasing/decreasing the distance between atoms. It is shown that the system of two atoms can be prepared in a separable mixed state with non-zero quantum discord that turns into an $X$-state for high laser field intensities. The behavior and relationships between the different correlations are studied and several limiting cases are investigated.

Effects of the Low Frequency Electromagnetic Field on the Centerline Macrosegregation of 7075 Aluminum Ingots

2011 ◽  
Vol 295-297 ◽  
pp. 1705-1708
Author(s):  
Dan Dan Chen ◽  
Hai Tao Zhang ◽  
Xiang Jie Wang ◽  
Jian Zhong Cui
Keyword(s):  
Electromagnetic Field ◽  
Steady State ◽  
Mushy Zone ◽  
Transition Region ◽  
Low Frequency ◽  
Casting Process ◽  
Direct Chill ◽  
Mushy Region ◽  
Chill Casting ◽  
Temperature Contour

The effects of the low frequency electromagnetic field on the macrosegregation of the 7075 aluminum ingots were investigated. The 7075 aluminum ingots with the diameter of 200 mm were prepared by the conventional direct chill casting and the low frequency electromagnetic field casting (LFEC) processes, respectively. The temperature during casting at steady state was measured, and the mushy region was observed from the temperature contour. The concentrations of the alloying elements were measured by the spectrograph. It was found that the transition region was broadened, but the mushy zone became narrower with presence of the low frequency electromagnetic field. The centerline macrosegregation of the ingots was alleviated by the low frequency electromagnetic casting process.

FACTOR SUBSTITUTION AND ECONOMIC GROWTH: A UNIFIED APPROACH

2012 ◽  
Vol 16 (4) ◽  
pp. 625-656 ◽  
Author(s):  
Jianpo Xue ◽  
Chong K. Yip
Keyword(s):  
Economic Growth ◽  
Steady State ◽  
Growth Models ◽  
Elasticity Of Substitution ◽  
Unified Approach ◽  
Factor Income ◽  
Factor Substitution ◽  
State Income ◽  
Per Capita ◽  
Relative Scarcity

This paper provides a unified approach to characterizing the relation between factor substitution and economic growth in different one-sector growth models (namely, the Solow, Ramsey, and Diamond models). Our main finding is that if better factor substitution raises savings in the steady state, then a higher per capita income results. There are two channels by which factor substitution affects savings: the positive efficiency effect via income and the ambiguous distribution effect via factor income shares. If the efficiency effect dominates, then a higher elasticity of substitution leads to a higher level of per capita steady-state income. In transition, factor substitution affects the rate of convergence both directly and through the equilibrium profit share. The former arises from diminishing marginal productivity of capital whereas the latter reflects its relative scarcity. Depending on the interaction of these effects, the net outcomes are characterized.

Accurate Motion Control of Linear Motors With Adaptive Robust Compensation of Nonlinear Electromagnetic Field Effect

2011 ◽  
Author(s):  
Zheng Chen ◽  
Bin Yao ◽  
Qingfeng Wang
Keyword(s):  
Electromagnetic Field ◽  
Steady State ◽  
Motion Control ◽  
Field Effect ◽  
Linear Motor ◽  
Adaptive Robust Control ◽  
Tracking Performance ◽  
Positioning Systems ◽  
Linear Motors ◽  
Driving Current

Iron-core linear motors have been widely used in high-speed/high-accuracy positioning systems due to the elimination of mechanical transmissions. Many control methodologies have been developed for linear motor motion control, such as H∞ control, adaptive control and sliding mode control. Compensations of various nonlinearities such as frictions and cogging forces have also been carried out to obtain better tracking performance. However, the relationship between the driving current and the resulting motor force has been assumed to be linear, which is invalid for high driving coil currents due to the saturating electromagnetic field effect. This paper focuses on the effective compensation of nonlinear electromagnetic field effect so that the system can be operated at even higher acceleration or heavier load without losing achievable control performance. Specifically, cubic polynomials with unknown weights are used for an effective approximation of the unknown nonlinearity between the electromagnetic force and the driving current. The effectiveness of such an approximation is verified by off-line identification experiments. An adaptive robust control (ARC) algorithm with online tuning of the unknown weights and other system parameters is then developed to account for various uncertainties. Theoretically, the proposed ARC algorithm achieves a guaranteed transient and steady-state performance for position tracking, as well as zero steady-state tracking error when subjected to parametric uncertainties only. Comparative experiments of ARC with and without compensation of electromagnetic nonlinearity done on a linear-motor-driven industrial gantry will be shown. The results show that the proposed ARC algorithm achieves better tracking performance than existing ones, validating the effectiveness of the proposed approach in practical applications.

Exact and approximate numerical solutions to steady-state single-server queues:M/G/1 ? a unified approach

1992 ◽  
Vol 10 (4) ◽  
pp. 351-379 ◽  
Author(s):  
M. L. Chaudhry ◽  
U. C. Gupta ◽  
Manju Agarwal
Keyword(s):  
Steady State ◽  
Numerical Solutions ◽  
Single Server ◽  
Unified Approach
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