A novel approach for improving the magnetic properties and reducing the power loss of FeSi3.5 composite at 200–500 kHz band

The easy-plane FeSi3.5 composite with excellent magnetic properties and power loss is proposed. The magnetic properties and power loss of the easy-plane FeSi3.5 composite are studied by using the none easy-plane FeSi3.5 composite as a control. This easy-plane FeSi3.5 composite has an initial permeability of 62, resonance frequencies of 100 MHz and 1.5 GHz, and frequency stability of 40 MHz. In addition, the easy-plane FeSi3.5 composite has also excellent loss properties, with a high-frequency power loss of only 108.12 kW/m3. The three kinds of power loss of the easy-plane FeSi3.5 composite are reduced compared with the none easy-plane FeSi3.5 composite through loss separation, especially the eddy current loss and the excess loss. The eddy current loss and the excess loss of the easy-plane FeSi3.5 composite are only 0.03 and 12.93 kW/m3 at 500 kHz, which reduce by 99.44% and 92% compared with the none easy-plane FeSi3.5 composite. Effective reduction of power loss and significant improvement of magnetic properties are important for solving the problem of power loss encountered by power electronic devices at the kHz band. Therefore, the application of the easy-plane FeSi3.5 composite with excellent power loss and high-frequency magnetic properties becomes a novel approach to meet the practical application of power electronics. The method that increases the working frequency and decreases the maximum magnetic flux density keeping the energy transformation efficiency constant is a new method to reduce power loss at the wide frequency band.