Affiliations: [a] Imperial College of Science, Technology and Medicine, Electrical and Electronic Engineering Department, Exhibition Road, London SW7 2BT, UK
Abstract: This work is concerned with the automatic design of electromagnetic devices in 3D using numerical methods, i.e., deterministic methods coupled with finite elements (FE). In particular this work considers the choice of deterministic methods, limitations concerning the number of variables, convergence, CPU time and choice of potentials for the field analysis. Two different approaches are considered for the sensitivity analysis, the direct differentiation of the FE matrices and the adjoint variable method. The FE formulation uses the magnetic vector potential for domains with current densities and the scalar potential for domains in which current densities are not present. The results of two static problems are presented. In general, the increase in the number of variables, from 2D to 3D, did not represent a major problem for the convergence of the methods studied. In terms of CPU time, the sequential quadratic programming method performed better than the augmented Lagrange multiplier method. Both sensitivity analysis methods investigated proved to require similar field calculations.
