Eddy Current Analysis using Singular Value Decomposition as Subdomain Solver

Abstract

A 3-D eddy current analysis based on the A-ϕ method with a domain decomposition method (DDM) has been proposed. In the 3-D eddy current analysis with the DDM, the conjugate orthogonal conjugate gradient with incomplete Cholesky factorization (ICCOCG) method is generally applied to solve subdomain problems because the coefficient matrices become singular. However, it is difficult to obtain high-accuracy solutions by using iterative methods because the solutions contain truncation errors. Regularization methods such as to fix gauges deteriorate the convergence of the iterative method. Therefore, we propose an improvement method of the convergence applying a direct method based on a singular value decomposition (SVD-direct method) as the subdomain solver. This proposed method has a merit that the A-ϕ method can be formulated. The improvement of convergence can be obtained with the SVD-direct method. In this paper, the algorithm of the proposed method is described, and improvement effects are shown through several experiments.