Time domain method for the nonlinear steady-state analysis of electromagnetic fields

A time domain method for the steady-state analysis of nonlinear electromagnetic fields is presented. Considering a stepwise time variation of the nonlinear parameters, a linear time varying system is derived from the nonlinear one. The time domain periodic solution of this system is determined analytically. Then, the nonlinear constitutive equations of the time varying parameters are imposed, obtaining a nonlinear system giving the actual time periodic values of the parameters. The method has been used to determine the time periodic solution of a volume integral equation method for the analysis of eddy current problems. In this case, the order of the nonlinear system of equations that govern the solution is determined by the discretisation of the ferromagnetic regions only