Abstract: A distribution of the steady magnetic filed in a very large ferromagnetic conductor of arbitrary, but known cross-section is determined using variational approach with Ritz's method for approximate solving of the problem. Then an axial component of the magnetic vector potential is presented as finite functtional series, automatically satisfying boundary condition that the normal component of the magnetic induction on the conductor's surface vanishes. The convergence and the accuracy of the proposed method are investigated. Several results for maps of the force lines and of the inductivity per unit conductor length are compared with corresponding numerical results obtained by Finite Element Method (program package FEMM) and excellent agreement is noticed.
Keywords: Steady mgnetic field, magnetic vector potential, ferromagnetic conductor, Ritz's method, Finite Element Method.