Search

Different techniques are investigated to improve the performance of the solution process of 3-D, time-periodic, nonlinear, voltage-driven eddy current problems under the influence of dc bias by the means of the finite-element method. The underlying nonlinear iteration technique is the time-periodic fixed-point method. The benefit of a static approximation to generate an initial solution, i.e., of a static initialization is pointed out. A secant method and a Schur complement technique to carry out the static initialization are compared. The procedures developed are applied to 3-D models of one- and three-phase benchmark transformer problems with dc bias. [ABSTRACT FROM AUTHOR]

Abstract: Two different techniques for the analysis of nonlinear, periodic eddy‐current problems are compared using a three‐dimensional benchmark problem. The methods are the parallel time periodic finite element method and the time periodic fixed‐point technique. [ABSTRACT FROM AUTHOR]

A method is presented for obtaining the steady-state solution of three-dimensional eddy current problems with nonlinear material properties and periodic excitations using the T,\Phi-\Phi formulation. The problem is formulated in the time-domain and the application of a fixed-point approach combined with a discrete Fourier-transformation technique ensures that, during one nonlinear iteration step, there is no coupling between the time-steps within one period. The steady-state result is hence obtained by solving half as many time steps as their number in one period. Since the time steps are decoupled, their computation can be readily parallelized resulting in a fast method. Comparison with results obtained by a transient time-stepping technique is presented. [ABSTRACT FROM PUBLISHER]

A method is presented for the optimal choice of the fixed-point reluctivity in nonlinear eddy current problems solved for steady-state in the frequency and the time domain. The optimal selection is shown to ensure a minimal contraction number for the fixed-point method. The proposed technique is compared to earlier approaches using a 2-D example. [ABSTRACT FROM AUTHOR]