Calculation of the surface effect in the ferromagnetic conductor with the harmonic electromagnetic field

Abstract

The authors of the paper have obtained formulas for analytical calculation of the constants with the harmonic electromagnetic field, which characterize the surface layer (a skin layer) of the ferromagnetic conductors in case of heating and nonlinear magnetic properties, which can be used for practical calculation of the electromagnetic screens, rotors of the electrical machines and inductive heating installations. A nonlinear dependence of the magnetic induction on the magnetic tension of the ferromagnetic conductor is replaced by one or two linear sections. It is considered that the skin layer of the conductor has constant quantities of the specific conductivity and averaged temperature. Linear electrodynamics equations are solved for the conductive half-space. Parameters of the ferromagnetic conductor's surface layer are calculated: magnetic permeability, the thickness of the skin layer and its averaged temperature, exposure time of the electromagnetic field on the conductor with the established maximum temperature on the conductor's surface, pressure of the field on the conductor and its resistance, inductivity of the internal magnetic field in the conductor, the thermal energy capacity. The methods credibility is confirmed with the concurrence of the resistance and inductiviry of the ferromagnetic conductor with analogous quantities from other methods.