2D 2D steady-state models 3D finite element method Fourier analysis Maxwell–Fourier method Voronoï tessellation analytical expression analytical method analytical model analytical modeling complex harmonic modeling eddy-current eddy-current losses electric machines electrical machines electromagnetic performances experiment finite iron relative permeability finite-element analysis high-speed hybrid analytical modeling hybrid excitation hybrid model linear induction motors loss reduction magnet shape optimization magnetic equivalent circuit magnetic equivalent circuits multi-phase multiphase induction machine