Adaptive time-stepping in nonlinear transient electromagnetic finite element analysis

Time-step size is automatically adapted to enable efficient convergence in nonlinear transient electromagnetic finite element computations. The adaptive time-stepping takes into account both induced eddy currents and the nonlinear reluctance matrix due to saturable B-H curves. The new algorithm is shown to obtain results that agree with fixed time-step methods, but with savings in computing time of up to 90%.