Alternating and Rotational Losses Up to Magnetic Saturation in Non-Oriented Steel Sheets

Abstract

A three-phase magnetizer has been developed, by which non-oriented Fe-Si steel sheets can be characterized under alternating and rotational flux up to a polarization value $J_{p}\approx 0.98~J_{s}$ , where $J_{s}$ is the saturation magnetization. The loss measurements, performed in the frequency range 2 Hz–1 kHz, require the combination of field-metric and thermometric methods, besides fine control of the induction wave-shape/loci under the required demanding exciting conditions. By exploiting the loss separation concept, it is observed that under rotational flux, both the hysteresis and excess loss components monotonically decrease with $J_{p}$ , to disappear at saturation. The measured losses then become equal to the calculated classical losses. This could actually be predicted, because of the expected disappearance of the domain walls under saturating rotational field, but it has never been previously verified by the experiments.