Search

The main objective of this paper is to provide an efficient computational model for fast and accurate calculation of electromagnetically induced vibrations in electrical machines. Although a three-phase permanent-magnet synchronous machine has been used in this paper, the same methodology can be extended to other types of electric machinery. A brief comparison between the different methods for structural analysis in electrical machines is introduced. The method proposed in this paper uses finite-element analysis in order to extract the impulse responses that are used in calculating the vibration. A field reconstruction method is used for the electromagnetic field analysis. [ABSTRACT FROM PUBLISHER]

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]

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 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]

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 calculation of voltages induced by external electromagnetic fields on multiconductor transmission lines (MTLs) has been the subject of several studies. In this paper, discrete equations for MTLs exposed to incident fields are derived based on the time-domain finite-element method and the backward differentiation formula. Based on these equations, a value-delivery table characterizing the MTLs is presented. Combining this table with modified node analysis formulation, it is convenient for analyzing the responses of transmission lines composed of complex termination networks or complex transmission-lines networks. The validity and efficiency of the proposed algorithm is demonstrated using several examples. Finally, a 1-km 35 kV overhead line above an imperfectly conducting ground is studied, and the influences of ground wire and a metal-oxide arrester to the lightning-induced voltage are both discussed. [ABSTRACT FROM PUBLISHER]

This paper presents a new neural-network method to describe the electromagnetic (EM) behavior at the interface between the substructures from an internally decomposed EM structure. A set of neural networks is used to represent the EM behavior of the substructure as seen from the interface. This allows EM coupling between substructures to be effectively represented. The method is developed in a finite-element environment. An EM transfer function matrix is formulated to produce training data, allowing neural networks to learn the spatial coupling between EM-field variables at various locations over the interface of the substructure. A new formulation is proposed where trained neural networks are integrated into the finite-element equation for efficient simulation of an overall EM structure. A technique is developed to allow the proposed model to be used with the mesh different from that in neural-network training. Examples show that the proposed method provides better accuracy than conventional neural-network approaches for modeling substructures from an internally decomposed EM problem. Using the proposed model also speeds up finite-element simulation. [ABSTRACT FROM AUTHOR]