Modeling of Fe-Based Soft Magnetic Materials for Multiphysical Analysis of Medium-Frequency Transformers

Fe-based soft magnetic material such as amorphous or nanocrystalline alloy is an alternative to the ferrite for magnetic cores of the medium-frequency transformers (MFTs) due to its high permeability and magnetic saturation. However, accurate core loss modeling is one of the major obstacles to design a high-power-density MFT, especially when considering the nonlinearity hysteresis B-H loop. Besides, the magnetostriction that exhibits hysteresis characteristic causes the vibration issue. Several studies have proven that the high intensity of acoustic noise will do harm to the human's mental and physical health. However, the research on the modeling of the acoustic vibration caused by magnetostriction has been scarcely conducted. In this article, the Jiles–Atherton (J-A) model is applied to describe the hysteresis characteristic of the B-H and H-strain for the Fe-based soft magnetic material. The J-A magnetic and magentomechanical hysteresis models were incorporated into the finite element analysis (FEA) under the multiphysics simulation environment in order to estimate the core loss and temperature rise of the MFT. The acoustic vibration FEA model of the MFT was built based on the H-strain hysteresis J-A model. The fidelity of the simulated acoustic noise pressure was verified by the experiment test results. The proposed models in this article can be effective tools to evaluate the hysteresis magnetic and magnetomechanical behavior of the core in the MFT.