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This paper proposes a way to represent the anisotropic nonlinear superconducting properties using a discrete model for magnetization with the corresponding critical parameters, equivalent to the Power Law model for currents. This simplified model makes it possible to analyze magnetic systems with superconducting elements in a stationary mode, which reduces the calculation time. Using of proposed model is demonstrated by the calculation of force interactions between high-temperature superconducting (HTS) samples and permanent magnet in zero-field-cooling (ZFC) and field-cooling (FC) modes. HTS bulks in the form of a prism and stack made of HTS tape are considered. The calculation of the electromagnetic field was carried out using the method of integral equations for field sources. The data of calculations are compared with the results of experimental studies. [ABSTRACT FROM AUTHOR]

This paper deals with the magnet pole shape design of permanent magnet machines for the minimization of torque ripple based on electromagnetic field theory. On the basis of a magnetic vector potential and a two-dimensional (2-D) polar system, analytical solutions for flux density due to permanent magnet (PM) and current are obtained. In particular, the analytical solutions for mathematical expressions of magnets with different circumferential thicknesses can be solved by introducing improved magnetization modeling techniques, resulting in accurate calculations of electromagnetic torque. The analytical results are validated extensively by nonlinear finite element method (FEM). Test results such as back-emf measurements are also given to confirm the analyses. Finally, on the basis of derived analytical solutions, a reduction of torque ripple can be achieved. [ABSTRACT FROM AUTHOR]

The aim of this paper is to highlight the capabilities of a new hybrid analytical modeling (HAM) approach for the analysis and design of various electromagnetic structures. After an introduction, where the aim of the development of this modeling approach is presented, the modeling approach is described. The new HAM is based on a strong coupling of the magnetic equivalent circuits method and analytical models (AMs). The AM, based on the formal solution of Maxwell’s equations, is established thanks to the separation of variables method. The HAM is applied to different permanent magnet electric machine structures, and the results are validated extensively by comparison with the finite-element analyses. [ABSTRACT FROM AUTHOR]

This paper deals with the dynamic characteristics of a linear induction motor (LIM) in terms of acceleration times and jerk conditions. We employed Matlab Simulink for conducting simulations of the dynamic modeling of LIM operated by a space vector pulse width modulation inverter. From the simulation results, the maximum load conditions and minimum acceleration times to guarantee passengers' safety were determined. Further, the electromagnetic field theory was employed to derive equivalent circuit parameters, and the results were validated by the finite element method. The analysis model was applied to a magnetic levitation vehicle for providing electromagnetic propulsion force, and its dynamic characteristics were analyzed to predict its operating performance; moreover, experimental results were employed to demonstrate the validity. We believe that the proposed prediction technique for the operating characteristics of LIMs can contribute to improving passengers' safety and riding quality. [ABSTRACT FROM AUTHOR]

A new wideband circular high-impedance surface (HIS) is proposed. Two models are developed to analyze the reflection characteristics of the proposed HIS. It is also shown through simulations that a circular HIS as a ground plane for loop antennas is superior to a rectangular HIS ground plane. The circular HIS was fabricated and a loop antenna was placed above it. Measurements were then performed and their results were compared with simulations. An excellent agreement was indicated. [ABSTRACT FROM PUBLISHER]

In this paper, a physics-based high-frequency (HF) model of switching power converters including the insulated gate bipolar transistor (IGBT) unit cells, heat sink, and connective printed circuit board (PCB) traces combined in a single electrical circuit is presented. The IGBT model includes the HF stray components superimposed on the well-known Hefner IGBT model. The HF components were calculated using a 3-D quasi-static finite element (3-D FE) analysis. The proposed complex model of the IGBT was verified both numerically and experimentally at different switching frequencies. The computed IGBT model was used in a low–high frequency model of a motor-drive system, and the common mode ground current was experimentally verified showing excellent results. [ABSTRACT FROM AUTHOR]

This paper presents SPICE models for the prediction of effects on shielded cables induced by nonuniform fields. Based on the transmission line theory, these models can be utilized to analyze shielded cables terminated with nonlinear or time-varying loads excited by nonuniform fields in the time domain. Two examples, a coaxial shielded cable and a two-parallel-wire shielded cable, both inside a cavity with a slot excited by an incident wave, are studied with the proposed models. The finite-difference time-domain method is employed to calculate the excitation fields of the cables, and then, the SPICE models are utilized to obtain the disturbances induced by the incident wave on the cables. The results obtained by the proposed models agree well with those obtained through other methods. [ABSTRACT FROM AUTHOR]

In this study, the design for a direct-drive permanent magnet (PM) wind power generator is presented, and its characteristics are analyzed based on analytical approach. In order to confirm their influence on the torque ripple characteristics, both the shape design and the skew effects of the PM are thoroughly studied. In particular, we performed an analytically based electromagnetic field analysis in order to investigate the influence of the AC/DC load conditions on our model. By manufacturing a model using an experimental construction setup, we validate the results of our analytical approach. [ABSTRACT FROM AUTHOR]