Analysis of Excess Loss in SiFe Laminations Considering Eddy-Current Dominated Domain Wall Motion

To develop efficient silicon steel plates and electric machines using silicon steel laminations, the evaluation of excess loss in silicon steel plates is important. In this paper, investigation on excess loss calculation using the finite element method is carried out. The excess loss, which is mainly due to two factors, lack of flux penetration and domain wall pinning, is considered by the proposed approach using the domain wall bowing degree (DWBD), which depends on the above two factors. The DWBD is obtained using nonlinear eddy-current analysis. The correlation between the excess loss and the DWBD can be expressed as an exponential equation. Using the equation, the excess loss can be predicted under harmonic frequency in the range of 50-2000 Hz. These results can be applied to iron loss estimation, especially, when there are harmonics in the power supply.