Magnetic Characterization of 4 μm-thick Steel Made by Continuous Rolling Process for Power Electronic Applications in High Frequency

This is the first study to experimentally perform the magnetic characterization of 4 mu m-thick electrical steel sheet based on the sinusoidal excitation technique at high frequencies of up to 1 MHz. The steel is made of pure iron, fabricated using a high-precision continuous rolling process, which is a suitable and effective method for mass production. One ring core in which the steel part is appropriately fixed on a plastic cylindrical chassis is fabricated for measurements, whereas another ring core without the steel part is fabricated to serve as a reference. In addition, a method for effectively estimating the magnetic flux density and relative permeability of the steel part in the first ring core from the measured data of the two ring cores is presented as a key contribution of this study. This method can also be applied in the magnetic characterization of other thin steels at high frequencies. The magnetic flux density-field intensity (B-H) curve, relative permeability, and iron loss per weight of the examined 4 mu m-thick steel are measured and evaluated through experiments. The measured results and Steinmetz approximation indicate that the eddy current loss in the investigated steel is relatively considerable at high frequencies of 500 kHz and above.

Automated summary

This study experimentally characterized the magnetic properties of 4 micrometer-thick electrical steel sheet at high frequencies up to 1 MHz. A method for effectively estimating the magnetic flux density and relative permeability of the steel part was proposed. The results showed that the eddy current loss in the investigated steel is significant at frequencies of 500 kHz and above.