Homogenization Technique of Nanocrystalline Cores Considering the Inter-Laminar Eddy Currents Due to Inter-Layer Contact

Abstract

The nanocrystalline core is widely used in high-frequency inductors for its outstanding performance of lower dynamic losses in high-frequency regions. However, the electrical isolation among strips is air gap but not absolute insulating coating like silicon steel sheets. To accurately calculate the iron loss of the nanocrystalline core, the inter-laminar eddy currents due to inter-layer contact should be considered. In this article, a homogenization technique of the nanocrystalline core is proposed considering the inter-laminar eddy currents. The flux distribution of the proposed method has a better agreement with the one obtained by the fine-meshed model than the result of the conventional homogenization technique. The simulation results show that a small contact area between strips can have a large increment of eddy current losses. Compared to the measurement results of the dynamic losses, the proposed method is validated.