Measurement of magnetic hysteresis swelling-up with frequency: impact on iron losses in electric machine sheets

This paper relates to the measurement and the modeling of iron losses in electric machines by studying the influence of frequency on magnetic hysteresis. Indeed, increasing frequency involves a swelling-up of the hysteresis loop, influencing several magnetic properties and so iron losses. The proposed study is to characterize a FeSi NO20 steel sheet under sinusoidal waveform at different level of magnetic flux density by varying the frequency. The measurements provide information about the magnetic behavior under frequency variation. Then, iron losses are decomposed to highlight their different components, as hysteretic or eddy current losses. The perspective of the study is to improve a quasi-static model of hysteresis based on the play model by turning it into a dynamic one. Finally, taking into account dynamic effect involves a far better accuracy of iron losses modeling.