A finite element computation procedure for electromagnetic fields under different supply conditions

A computational procedure is developed to analyze two-dimensional nonlinear electromagnetic fields in steady-state alternating conditions both when the currents in the conductors are specified and when the voltage sources and the electrical connections are assigned; furthermore the effects of eddy currents can be included. In every case the finite element and Fourier approximations and the iterative method employed to handle magnetic nonlinearities lead to a set of linear algebraic systems having the same block structure. The application of the procedure is illustrated by analyzing a no-load three-phase transformer neglecting eddy currents and a high-frequency single-phase transformer including the skin effect.