Numerical calculation of nonlinear transient field problems with the Newton-Raphson method

The modeling and numerical simulation of transient electromagnetic field pr oblems with ferromagnetic materials is described in the context of the Fini te Integration Technique (FIT), This paper presents a Newton-Raphson method adapted to FIT which is faster than the Successive Approximation technique . Due to the nonlinear material behavior these algorithms are not always st able, In order to improve convergence, a dynamic relaxation process and a s uitable interpolation of the magnetization curve are presented. Results of these iterative schemes are compared with measurements of typical benchmark problems.