3D eddy current analysis by the finite element method using double nodes technique

There are several difficulties in calculating eddy currents in plates with thin slits by the finite element method (FEM). Under the influence of flat finite elements at slits, the accuracy of analysis decreases and the computation time increases. Using the A-φ method, we propose a novel technique, which overcomes those defects. The feature of the method is to adopt double nodes for the electric scalar potential φ at slits, but not to the magnetic vector potential A. Adopting this technique, slits are equivalent to current barriers that have infinitesimal width. Some numerical results, which show the validity of the proposed method, are also presented. We analyze the magnetic fields of a double-sided linear induction motor with slits in a secondary plate, as a suitable model for proving the validity of the proposed method