Fast solution techniques in 3D electromagnetic field problems

A fast Newton-Raphson Technique (FNR) for the computation of nonlinear three-dimensional finite-element magnetic fields in electrical devices is presented. The technique reduces by more than 50% the CPU time required for complete and converged nonlinear three-dimensional magnetic field solutions. This is in comparison with the standard Newton-Raphson (NR) technique. The significant reduction in CPU time was achieved without any sacrifice in the accuracy of the converged three-dimensional magnetic field solutions or in the values of the device terminal parameters. To illustrate the advantages of the method, a single-phase transformer was implemented with widely varying degrees of magnetic saturation. Values of magnetic vector potential, as well as flux density components obtained using the FNR technique were compared with the values obtained using standard NR method. Furthermore, the saturated values of magnetizing inductances were obtained and compared using the fast and standard NR methods.<
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