Temperature Dependence of Powder Cores Magnetic Properties for Medium Frequency Applications

Soft magnetic powder cores are attractive due to their loss at medium frequency. However, the performance of electrical equipment is affected by temperature increase by the heat of core losses. In this paper, the magnetic properties of nanocrystalline powder core, amorphous powder core, X-Flux (Fe-Si), Sendust (Fe-Si-Al), and ferrite are measured and compared in the range of 25 °C to 125 °C from 20 kHz to 100 kHz. The discussed magnetic properties include the temperature dependent coercive field, initial permeability, inductance factor, saturation flux density, and core loss. The results show that magnetic properties depend on temperature and frequency. In comparison, the nanocrystalline powder core has the best temperature stability and relatively low core loss among the five materials, so it can be well used at broad temperature and medium frequency.