Effect of mechanical stress on different core loss components along orthogonal directions in electrical steels

The paper deals with the characterization and modelling of the mechanical stress dependency of magnetic losses along two orthogonal directions in non-oriented electrical steels. Significant anisotropy effects are highlighted. Using the three-term loss-separation approach, the different loss components are computed at each stress level for a wide range of frequency. Stress dependence of the core losses can be described in terms of the hysteresis and excess loss components, classical losses being assumed to be constant as a function of stress. Variations of the model coefficients with stress along the two principal directions are discussed. Such a model can be used for computing the losses in finite element analysis of rotating electrical machines or T-joint of transformers.