Exact minimization of energy functional for NR method with line-search technique

The line-search technique was usually introduced to the Newton-Raphson (NR) method in order to improve the convergence characteristic of nonlinear magnetic field analysis with the toughness magnetic nonlinearlity. In this paper, we proposed the NR method combined with the optimal step size using exact functional minimization in every nonlinear iteration. The convergence process and computation time were investigated, and compared with the conventional line-search technique using the approximate functional minimization. Index Terms--Energy functional, exact minimization, line-search, Newton-Raphson (NR) method, nonlinear magnetic field analysis.