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A new integral algorithm is proposed for electric field evaluation around HVDC transmission line. Updating of charge density, which involve repeating iteration and complicated physical analysis, is avoided. And considering the surface charge as unknown variables, a set of quadratic equations are developed on the base of the potential continuity of and current, and from which the distribution of space...
A novel three-dimensional FE procedure for the analysis of electron guns inside TWT is presented, illustrating its main features. In this procedure electron trajectories modeling cathode emission are obtained by solving a Vlasov-Poisson system of equations together with relativistic dynamical equations of motion, under consistent injection condition. This coupled electro-mechanical problem is solved...
The analysis of foundation grounding systems buried in a horizontal multilayer soil is presented by means of fictitious conductivity concept. The calculation can be simplified as grounding systems in a multilayer soil with equivalent current sources added on foundation surfaces. Therefore existed codes based on the moment method can be combined easily. Numerical examples show the effectiveness of...
With reference to the 2D magnetic field analysis by the surface-current method, this paper describes a new procedure with analysis of rotating magnetic device by surface current method. This procedure improve convergence speed and less calculation time than FEM code. This method has been tested and simulation results has compared with FEM code
The corona generated from ultra high-voltage direct-current transmission lines can affect the environment nearby. Based on the finite element method, an iterative algorithm to analyze the electric field and the ion current density at the ground level generated from the bundled conductors of bipolar lines is proposed. After the validity of the method is testified, some examples are analyzed
The mathematical homogenization theory is applied to the thin-shell formulation for the analysis of the shielding effectiveness of magnetic and pure conductive shielding structures. The numerical results are validated by comparison with a standard approach modeling the non-homogenous domain
This article reports a simple application of least-squares finite element method (LSFEM) to magnetostatic and eddy-current field analyses. The computational accuracy of the LSFEM is compared with that of the Galerkin FEM. The LSFEM can yield an accurate eddy-current field if the boundary condition is given properly
2D multipolar expansion is extended to account for externally created field and numerous relations are derived. The most general field created outside or inside a cylinder can be created by a current density flowing axially on the surface of the cylinder. Such a surface current can also cancel the field generated either inside by external sources or outside by internal sources. Knowing 1 field component...
A new electric-field cage is described, capable of generating uniform DC or quasi-static AC electric fields for sensor calibration and testing. This unique facility is a large parallel-plate capacitor with guard rings to control fringing fields. The cage dimensions and endplate voltages can be adjusted to meet the needs of a variety of experiments. The current size is 2.4 m high by 3.0 m wide (endplates)...
Maxwell laws and constitutive laws are different in nature and consequently they impose different requirements on basis functions used in numerical techniques. In other terms, there is a need for basis functions for which exterior derivative and Hodge star simultaneously make sense (together with reasonable smoothness conditions). We introduce a formal approach that sheds light on these matters
Soft magnetic composite (SMC) materials are particularly suitable for construction of electrical machines with complex structure and 3D magnetic flux. For design and analysis of such 3D flux machines, 3D magnetic properties of the magnetic materials should be properly determined, modeled and applied for calculating the magnetic field distribution, parameters and performance. This paper presents the...
For taking account of the two-dimensional magnetic properties of grain-oriented electrical steel, the effective anisotropic tensor reluctivity is examined, and a computationally efficient algorithm is suggested by using response surface method (RSM) to smooth the two-dimensional magnetic properties. It is shown that the reconstructed two-dimensional magnetic properties are fairly effective to stabilize...
The paper presents a methodology for determination of harmonic iron losses in laminated iron cores under non sinusoidal excitation. The method is based on a convenient modification of Jiles-Atherton model to account for dynamic effects. The model tuning is performed by using measured hysteresis loops in iron laminations for sinusoidal excitation of various frequencies in Epstein device. An example...
The main purpose of this paper is to describe a novel ultrasonic motor which is suitable for small information devices. With a bimorph structure having relatively large displacement, applied voltage and frequency could be reduced. From simulated results, such as mode and harmonic analysis, operating frequency and resonance mode are determined. In order to improve the performance of motor, several...
In this paper an ab-initio calculation that allows to describe the main features of permalloys is presented. The calculation is based on Korringa-Kohn-Rostoker electronic structure method. The dependence of magnetocrystalline anisotropy and of the magnetostriction on the concentration of non magnetic addiction is computed
The possibility to introduce microscopic dissipative processes before solving a macroscopic magnetodynamic problem is investigated. Both scales are derived from the same energy-based description
This paper deals with the rotating electromagnetic field diffusion into hysteretic materials. A simplified vector formulation based on a parallelogram hysteresis model has been investigated, in order to significantly reduce the computational effort. Vector saturation and loss properties are discussed. Whole simulation has been done by the use of a finite element time domain algorithm
The Preisach hysteresis model was implemented for description of GMR layered structures behavior. A computation of behavioral characteristics is based on experimentally obtained distribution probability function of elementary hysteresis structure fragments. The experimental results show the opportunity to study the relations between microstructural properties and external functionality of GMR structure
The Preisach distribution function is determined for a grain-oriented electrical steel sheet using two methods: using hysteresis curves, and inverse algorithm method. The methods are combined with finite element method, and the convergence characteristics are compared
This paper proposes a high frequency transformer model. The model consists of power frequency transformer model connected in parallel with frequency dependent branch (FDB). The FDB branch represents the transformer high frequency behavior over wide frequency range. The frequency response of the transformer was obtained by coupling the transformer FE model and external electric circuits. Such a technique...
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