A computer controlled measurement system based on National Instruments Data Acquisiton card and National Insturments LabVIEW software package has been built. First, the hysteresis characteristics of the tested specimen have been simulated by Jiles-Atherton model, and simulated measurements have been performed using LabVIEW functions. This work is a preliminary study of LabVIEW and the measurement of hysteresis. The main goal is to control the magnetic flux density measured on a toroidal shaped core with a feedback controller. In this paper, the developed procedure, which is able to measure the hysteresis characteristics applying analogue and digital integrators, and to control the waveform of magnetic flux density determined from the voltage induced in the secondary coil wound on the toroidal shaped core is presented. The experience proves that the developed controller is stable and robust. This work is an initial step of the vector hysteresis measurement system.
The paper reports about the building up a computer controlled measurement system based on National Instruments Data Acquisition card and National Instruments LabVIEW software package. The aim of this research is to detect manufactured surface cracks on steels by applying a magnetic flux leakage testing method. First of all, a finite element method based on the procedure to analyze the behavior has been implemented of the measurement system under construction. One important question is the position of the sensors or of the detecting coils. The finite element procedure contains a two dimensional arrangement. First, eddy currents have been neglected, but the nonlinear characteristic of the specimen has been taken into account by a single valued function. In this paper, the developed measurement system, which is partially ready to work, and the nonlinear finite element procedures are presented as well.
The paper deals with an eddy current field problem as a case study. The aim is to find the solution of the problem by the help of the Finite Element Method (FEM), and the
T, Φ, Φ
potential formulation taking the nonlinearity of the material into account. The effect of nonlinearity has been approximated with an inverse tangent type analytical model. The nonlinearity has been handled by the polarization method coupled with the Fixed-point iteration technique.
The design of inductors is not an easy and cheap task considering the dimensions, the nominal value of inductance, the quality factor and the impedance of the component. Before the beginning of manufacturing a new type of inductors, a lot of trial components have to produce, have to measure and have to try out. Finite element modeling is a well-tried process to examine engineering products before manufacturing them. To reduce the cost and the time of the design process, in the paper a finite element model has been built up to simulate inductors. In the paper the model is presented, which is able to simulate the important attributes of the component, for example the inductance, the impedance and the quality factor. The comparison of the experimental and the simulated attributes of the inductor will also be shown. By using the built up model the development possibilities of the inductor have been examined through the modification of the winding.
The paper presents the analysis of nondestructive testing equipment under investigation. There are two main parts of the research as well as this paper. The first part shows the present state of the developed nondestructive tester based on the Magnetic Flux Leakage method, the other part reviews the simulation and the results, which have been made with the principle of the Finite Element Method. The aim now is to define the order of magnitude of the magnetic flux density in the positions of the sensor.
The paper deals with the analysis of the single-phase induction motor of Problem No. 30a of the COMPUMAG TEAM Workshop. The problem has been solved by the motional two-dimensional time-harmonic Finite Element Method (FEM) using different potential formulations, the
, -potential formulation and the
-potential formulation. Here the problem is a linear eddy current field problem.
The paper presents the numerical modeling of a Y-shaped three-pole radial magnetic bearing based on two-dimensional (2D) and three-dimensional (3D) magnetic field computation with nonlinear model of the material. The used numerical method is the Finite Element Method (FEM). The nonlinear system of equations according to the nonlinear characteristics of ferromagnetic material can be handled by the Newton-Raphson technique and by the fixed-point method.
Sensitivity is the most important parameter of the Transponder coils from the performance point of view. Due to the open magnetic circuit constructions analytic formulas are not available and not applicable to calculate the sensitivity. Analogically to the self-inductance effective permeability a similar effective permeability can be introduced for the mutual inductance, as well. The presented sensitivity calculation method is based on the mutual effective permeability. By the presented method, the sensitivity of inductors with arbitrary shape and permeability materials can be calculated with good accuracy.
The paper presents a parallel approach for the efficient solution of a simple 1D Laplace-Poisson equation problem by parallel finite element method. This problem is a case study. The non-overlapping domain decomposition method has been used to cut the problem into sub-regions or also called sub-domains, and it reduces the large mass matrix into smaller parts. The independent subdomains, and the assembling of these equation systems can be handled by the independent processors of a supercomputer, i.e. in a parallel way. The results of parallel finite element method have been compared to the results of serial finite element method as well as the analytical results.
Koch curve based dipole antennas have been built up, have been simulated and measured to examine the reachable size reduction.The simulations have been performed by the method of moments (MoM) and the results have been checked by the finite element method (FEM) and by measurements. The Pocklington’ integral equation has been implemented in MATLAB environment to simulate the input impedance of dipole antennas. The ATW EFIE method has been implemented and solved by the 4NEC2 software to examine the behavior of arbitrary shaped thin wire antennas. In COMSOL Multiphysics software environment a finite element model has been set up to solve the Helmholtz equation and to simulate the antennas under examination. Koch curve based dipole antennas have been measured in a full anechoic chamber, as well and finally the numerical and the experimental results have been compared.