Nonlinear eddy current analysis by BEM for thin plate employing simple iterative approach

Abstract

Nonlinear eddy currents induced in steel plate are formulated by the boundary integral equations. The integral equations for the nonlinear analysis are derived by regarding nonlinear terms as fictitious sources. As the periodic electromagnetic quantities in the steel plate are distorted, these fields are expressed with the help of Fourier series, whose fundamental and harmonic fields are determined by solving the corresponding integral equations with the surface magnetic fields given as the boundary values. The internal and surface electromagnetic fields are obtained numerically one after the other until convergence. In this iterative solution, Newton-Raphson method has been adopted but it is not applicable if the plate thickness approaches zero. So as to solve the difficulty, we adopt a simple iterative method and have confirmed that the method is effective.