Calculation Of Magnetic Flux Density Research Articles

Flux Leakage Analytical Calculation in the E-Shape Stator of Linear Rotary Motor With Interlaced Permanent Magnet Poles

The circumferential and axial widths of permanent magnet (PM) pole and E-shape stator pole of linear rotary motor with interlaced PM poles are very influential to the back electromotive force (EMF) and the flux leakage analysis is complex, which causes difficulty in optimization of the motor structure. One of the key issues in optimization design is to calculate the flux leakage accurately. In this article, the main flux and side flux variation laws of stator pole are derived by analytical method. The flux leakage can be divided into the flux leakage between the PM and the mover, flux leakage on the stator tooth tip, and the flux leakage between the adjacent PM poles and stator pole. The 3-D flux leakage calculation model is built, which is suitable for the calculation of magnetic flux based on different motor operating principles. Then the rotational and rectilinear back EMFs are calculated by analytical method, which are consistent with the results analyzed by 3-D finite element method.

Measurement and Calculation of Magnetic Flux Density During Mold Electromagnetic Stirring on a Continuous Casting Bloom Mold

Measurement and Calculation of Magnetic Flux Density During Mold Electromagnetic Stirring on a Continuous Casting Bloom Mold

Calculation of Magnetic Flux Density Harmonics in the Vicinity of Overhead Lines

This paper considers the method for the calculation of magnetic flux density in the vicinity of overhead distribution lines which takes into account the higher current harmonics. This method is based on the Biot–Savart law and the complex image method. The considered method calculates the values of the magnetic flux density for each harmonic component of the current separately at all points of interest (usually lateral profile). In this way, it is possible to determine the contributions of individual harmonic components of the current intensity to the total value of magnetic flux density. Based on the contributions of individual harmonic components, the total (resultant) value of the magnetic flux density at points of interest is determined. Validation of the computational method is carried out by comparison of the results obtained by the considered calculation method with measurement results. Furthermore, the application of the calculation method was demonstrated by calculating magnetic flux density harmonics in the vicinity of two overhead distribution lines of typical phase conductor arrangements.

Calculations of Capacitive Take-off Power (CTP) from High Voltage Transmission Lines.(Dept.E)

This paper presents the constructions of capacitive take-off power (ctp) networks in different countries .Also, this paper illustrates the effect of switches on the stability of the network he station antena is built by connecting capacitive part of networks consisting of some condensers in specific arrangement-This arrangement Of each type has series of specific singularities. The presented analysis of uses a technique that divides the problem into two parts; firstly, the capacitive condengers and reactors selection calculations; secondary, calculation of take-off power antena. Also, lt presents a mathematical modelling of the transient processes in a capacitive take- off power network. This model is based on the calculation of magnetic flux of a single -phase two-winding transformer. This model is represented by non-linear equations. The short circuit occurs along the steel core and the leakage flux coupling the separated coils closes out the side of core. The mathematical model is developed to investigate the conditions of transient process analysis in a capacitive take-off power network. The reduction of overvoltage during short circuit period is also studied in this paper. Also, this paper suggests the solution algorithm using programme techniques. The final results and conclusions are presents.

Quick Calculation of Magnetic Flux Density in Electrical Facilities

The World Health Organization (WHO) warns that the presence of magnetic fields due to the circulation of industrial frequency electrical currents may have repercussions on the health of living beings. Hence, it is crucially important that we are able to quantify these fields under the normal operating conditions of the facilities, both in their premises and in their surroundings, in order to take the appropriate corrective measures and assure the safety conditions imposed, in force, by regulations. For this purpose, CRMag® software has been developed. Using the simplified Maxwell equations for low frequencies, CRMag® calculates and represents the magnetic flux density (MFD) that electrical currents produce in the environment. Users can easily model electrical facilities through a friendly and simple data entry. MFDs calculated by CRMag® have been validated in real facilities and laboratory tests. With this software, exposure levels can be studied in any hypothetical scenario, even in inaccessible zones. This allows designers to guarantee that legal limits (occupational, general population, or precautionary levels related to epidemiological studies) are fulfilled. A real case study has been described to show how the reconfiguration of conductors in a distribution transformer substation (DTS) allows significant reductions in MFD in some points outside the facility.

Regression models for magnetic flux density using DoE techniques and geometric optimization of MR valve

Magnetorheological (MR) fluids have found wide application in engineering devices, especially, in MR dampers. Calculation of magnetic flux density in the MR valve plays a critical role in the performance analysis of MR dampers. In the present study, regression models have been fitted for magnetic flux densities in the active and core regions of the MR valve for a commercially available MR fluid. The fitted model is presented as a function of the MR valve’s geometric parameters and applied current. For fitting the regression model, simulation experiments have been performed in ANSYS-APDL software using different design of experiment (DoE) techniques. For each technique, the model is improved upon by p-value test and the best model among different DoE techniques is selected by analyzing the coefficients of determination. The best-improved models are then used for geometric optimization of MR valve in the MATLAB® environment and the optimal results are compared to the one obtained from the approximated magnetic circuit with constant relative magnetic permeability.

Coil current and vacuum magnetic flux calculation for axisymmetric equilibria

In fixed-boundary axisymmetric equilibrium calculations the plasma shape is assigned from input. In several circumstances, the plasma shape may not be known a priori, or one may desire to also compute the magnetic field in the volume surrounding the plasma through the calculation of a free-boundary equilibrium. This requires either the coil currents or the magnetic poloidal flux on a curve in the vacuum region to be assigned as input for the free-boundary equilibrium calculation. The FREE-FIX code presented in this article is a general tool for calculating coil currents being given a fixed-boundary calculation. A new formulation is presented, which considerably reduces the computational cost of the calculation. FREE-FIX performs well for different geometries and experiments.

FEM Aided Design of Distribution Transformer

Computer aided procedure for design of distribution transformer is implemented on transformer type ETN 50-1-/0.4 a product of “EMO” company. All transformer parameters are calculated in Matlab as well as operational characteristics of voltage variation and efficiency factor at different type of loads and variation of secondary voltage for different secondary currents. The obtained results are compared to the experimental data from the producer. Finite Element Method (FEM) is implemented for calculation of distribution of magnetic flux density in transformer cross section for different operating regimes: no-load and rated load. FEM calculations are based on data obtained from transformer design. They enable electromagnetic processes inside the machine to be analyzed and accurate calculation of magnetic flux density to be done.

An analytic electromagnetic calculation method for performance evolution of doubly fed induction generators for wind turbines

An analytic electromagnetic calculation method for doubly fed induction generator (DFIG) in wind turbine system was presented. Based on the operation principles, steady state equivalent circuit and basic equations of DFIG, the modeling for electromagnetic calculation of DFIG was proposed. The electromagnetic calculation of DFIG was divided into three steps: the magnetic flux calculation, parameters derivation and performance checks. For each step, the detailed numeric calculation formulas were all derived. Combining the calculation formulas, the whole electromagnetic calculation procedure was established, which consisted of three iterative calculation loops, including magnetic saturation coefficient, electromotive force and total output power. All of the electromagnetic and performance data of DIFG can be calculated conveniently by the established calculation procedure, which can be used to evaluate the new designed machine. A 1.5 MW DFIG designed by the proposed procedure was built, for which the whole type tests including no-load test, load test and temperature rising test were carried out. The test results have shown that the DFIG satisfies technical requirements and the test data fit well with the calculation results which prove the correctness of the presented calculation method.

Corrigendum to "Time-varying magnetotail magnetic flux calculation: a test of the method" published in Ann. Geophys., 27, 1583–1591, 2009

FSPR=0.91FD+0.26, cc=0.99 FSPR=0.99FD+0.19, cc=0.94 lobes FPR96=0.70FD+0.35, cc=0.96 FPR96=0.66FD+0.29, cc=0.94 beta=0.1 FSPR=0.88FD+0.19, cc=0.79 beta=0.5 FSPR=0.83FD+0.21, cc=0.70 beta=1 FSPR=0.86FD+0.18, cc=0.70 neutral sheet FSPR=0.7 1 FD+0.20, cc=0.67 FPR96=0.84FD+0.24, cc=0.75

2차 보간법을 사용한 유도전동기 최대효율제어

3개의 자속에 대한 유도전동기의 입력을 계산한 후 3점을 2차 보간하여 2차 함수를 만들고, 입력이 최소가 되는 새로운 자속을 구한 후, 이 자속을 이용하여 다시 2차 보간하여 입력이 최소가 되는 자속을 구하는데, 새로운 점을 사용한 2차 보간을 수렴조건을 만족할 때까지 반복해서 입력이 최소가 되는 자속을 구하는 방법을 제안한다. 시뮬레이션 결과 최대효율제어를 위한 자속으로 신속한 수렴이 가능함을 보인다.

Time-varying magnetotail magnetic flux calculation: a test of the method

Abstract. We modified the Petrinec and Russell (1996) algorithm to allow the computation of time-varying magnetotail magnetic flux based on simultaneous spacecraft measurements in the magnetotail and near-Earth solar wind. In view of many assumptions made we tested the algorithm against MHD simulation in the artificial event, which provides the input from two artificial spacecraft to compute the magnetic flux F values with our algorithm; the latter are compared with flux values, obtained by direct integration in the tail cross-section. The comparison shows similar time variations of predicted and simulated fluxes as well as their good correlation (cc>0.9) for the input taken from the tail lobe, which somewhat degrades if using the "measurements" from the central plasma sheet. The regression relationship between the predicted and computed flux values is rather stable allowing one to correct the absolute value of predicted magnetic flux. We conclude that this method is a perspective tool to monitor the tail magnetic flux which is one of the main global magnetotail parameters.

Easy calculation of magnetic flux

In this paper, we give a very simple geometrical method to facilitate the calculation of the magnetic flux in some common cases where the magnetic flux density B produced by an infinitely long, straight wire carrying a steady current is considered. The method is also valid for vector fields with the same symmetry.

Mathematical Modelling of Transient Processes in The Capacitive Take-off Power Network.(Dept.E)

This paper presents a mathematical modelling of the transient processes in a capacitive take-off power network. This model is based on the calculation of magnetic flux of a single-phase, two-winding transformer. This model is represented by non-linear equations. The short circuit occurs along the steel core, and the leakage flux coupling the separated coils closes out the side of core. The mathematical model is developed to investigate the conditions of transient process analysis in a capacitive take-off power network. The reduction of overvoltage during short circuit period is also studied in this paper. Also, this paper suggests the solution manner using programme techniques. The final results and conclusions are presented.

A three dimensional magnetic field analysis by a novel finite element method using magnetic flux density directly as an unknown variable

A rigorous formulation for the analysis of three-dimensional magnetic field problems based on a novel finite-element method is presented in which the magnetic flux density is used directly as an unknown variable. Unlike solutions obtained by using scalar or vector potential, the results ensure continuity of the magnitude of the magnetic flux density vector between adjacent elements in a medium, and the accuracy of the magnetic flux density is much higher than with the traditional method. Furthermore, a subdivision coarser than that of traditional method can be used to obtain the same accuracy in the calculation of magnetic flux density, so that the memory required can be reduced. Some simple examples are provided.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>