Methods for magnetically nonlinear problems involving significant hysteresis and eddy currents

The authors consider the modelling of magnetic saturation and hysteresis within finite-element eddy-current calculation procedures. Specific attention is given to time-stepping methods which deal with both saturation and hysteresis and to single-harmonic time-periodic approximations for cycle problems. It is shown that time stepping results are very close to measured losses in cases where there are significant saturation, hysteresis, and eddy currents. It is also shown that periodic approximations can produce solutions which also agree well on loss but rather less well on other parameters, particularly stored energy. Rotation field components are shown to be a major modelling problem