Magnetic analysis of permeability configurable nanocrystalline flake ribbons for medium frequency energy conversion applications

The novel permeability configurable nanocrystalline flake ribbons (NFR) utilizing Fe-based nanocrystalline material has been increasingly adopted in diverse energy conversion applications. However, the applicationoriented magnetic properties are rarely examined. In this paper, the flexible NFR materials with different permeabilities are measured while the influence of permeability configuration is analyzed regarding the initial and amplitude permeabilities, B-H curves, and core losses. A measurement method using a full bridge inverter and LCL compensation is designed to test the magnetic material under various flux densities and in the frequency range between 50 kHz-150 kHz. In addition, ferrite materials with similar permeabilities are also tested for comparison. Results reveal that the NFR materials exhibit superior stability in terms of amplitude permeability changes and saturation capability compared with ferrites. Core loss grows with increased crushing, but permeability becomes more stable at higher frequencies. Hence, NFR materials can be matched to various applications based on their characteristics with different permeabilities. Additionally, the NFR materials have shown lower loss densities than their ferrite counterparts at high flux density conditions. Hence, the NFR material can be beneficial to achieve higher power density. Through analysis and experiments, this paper provides measurement optimization bases for practical energy conversion applications.