ABSTRACT
The variability of magnetic permeability into the depth of solid metal influences essentially the electromagnetic field as well as the active and reactive power loss distribution inside ferromagnetic metals. This chapter presents the most important known linearization methods for one-dimensional sinusoidal electromagnetic field. Due to numerical calculation difficulties, especially for 3D field problems, there are currently, simple, substitute methods in which the nonlinearity is considered as a kind of correction to the linear theory. The numerical method belongs to the most accurate physical and mathematical descriptions of the alternating field penetration into a solid steel, although it is still a simplified method. A full 3D analysis possibility, however, has appeared since the authors developed the numerical model of equivalent magnetic circuit, based on the 3D reluctance network method (RNM-3D), and the interactive computer program, RNM-3D.
