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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. [ABSTRACT FROM PUBLISHER]

In this paper, a synthesis of design methodologies for electromagnetic devices made with soft magnetic composite (SMC) material is presented. To realize efficient and low-cost SMC devices, it is necessary to benefit from interesting isotropic SMC material properties such as 3-D flux circulation path. In this case, the best approach is to carry out a topological structure research and perform a global optimization using physical models. However, the iterative optimization process can be computationally intensive and some compromises should be found between accuracy and computation time. One way is to use coarse models with important simplifying hypotheses but the optimal solution is often not valid. In this case, one can perform a limited number of finite element (FE) simulations to compute some correction coefficients and improve optimization convergence to a valid optimal solution. Another way is to perform the device optimization by using directly FE models with low mesh density and several simplifications of the device geometry. Such design approaches are illustrated by three concrete realizations with SMC material. [ABSTRACT FROM AUTHOR]

The paper presents a method for the estimation of the iron losses under PWM (Pulse Width Modulation) flux supply conditions. The computational results are validated versus measurements on Epstein's yoke. The proposed model is based on Finite Element method formulated in the harmonic domain and takes into account ferromagnetic hysteresis and eddy currents. A classical Preisach model is used for hysteresis modelling neglecting the effects of excess losses in field analysis. Different PWM supply conditions are measured and simulated with satisfactory agreement. [ABSTRACT FROM PUBLISHER]