Nonlinear Eddy Current Analysis by BEM Minimum Order Formulation

The eddy current induced in nonlinear material such as steel is formulated with the help of the boundary integral equations of the minimum order for the calculation of 3-D eddy current problems. The integral equations for the nonlinear analysis are derived by considering nonlinear terms as fictitious sources. Since the periodic electromagnetic fields in the steel 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.